What is the circumference of a
circle with a radius of 2.09 in

Answers

Answer 1
you do 2.09x2 to get the diameter then times that by pi to get 13.13 to 2 decimal places
Answer 2

Answer:

The circumference formula is C=3.14d

Step-by-step explanation:

To find the diameter with the radius you need to multiply 2.09 x 2.

Now you have 4.18, this is your diameter, you're now going to multiply 4.18 with pi, which is typically 3.14, if it's not that it's 22/7.

Your answer would be 13.12


Related Questions

How many powers of 7 are contained in 10?

Answers

There is only 1 power of 7 contained in 10.

Students use powers of numbers to solve this problem and learn what is occurring to the numbers as a result.

Students also learn how to divide a seemingly vast and challenging equation into smaller, more accessible components. The pupils should understand that raising 7 to a power only produces a finite number of unit digits. Furthermore, as the power of 7 rises, these particular numbers "circle round." 7, 9, 3, and 1 make up this cycle.

The digit in the tens place is the same.

The total number of times we multiply a number is known as its exponent or power. For instance, 2 to the power 3 denotes a 3x3 multiplication of 2.

The largest power of 7 that is less than 10 is 7^1 = 7, therefore there is only 1 power of 7 contained in 10.

To know more about exponents visit :

https://brainly.com/question/30066987?referrer=searchResults

#SPJ4

There is only 1 power of 7 contained in 10.

Students use powers of numbers to solve this problem and learn what is occurring to the numbers as a result.

Students also learn how to divide a seemingly vast and challenging equation into smaller, more accessible components. The pupils should understand that raising 7 to a power only produces a finite number of unit digits. Furthermore, as the power of 7 rises, these particular numbers "circle round." 7, 9, 3, and 1 make up this cycle.

The digit in the tens place is the same.

The total number of times we multiply a number is known as its exponent or power. For instance, 2 to the power 3 denotes a 3x3 multiplication of 2.

The largest power of 7 that is less than 10 is 7^1 = 7, therefore there is only 1 power of 7 contained in 10.

To know more about exponents visit :

brainly.com/question/30066987?referrer=searchResults

#SPJ4

9m-4n=1

11m-3n=5 in simontaneous equation

Answers

The values of the variables are n = -17/31 and m = 23/93

How to determine the values

From the information given, we have the equations;

9m-4n=1     equation 111m - 3n = 5   equation 2

To solve the simultaneous equation, we have to take the following steps

Make 'm' the subject from equation 1

9m = 1 + 4n

Divide both sides by 9, we get;

m = 1 -4n/9

Substitute the value into equation (2), we have;

11(1 -4n/9) - 2n = 5

expand the bracket

11 - 44n/9 - 2n = 5

find the LCM

11 - 44n - 18n  /9 = 5

cross multiply

11- 62n = 45

collect like terms

-62n = 45 - 11

-62n = 34

Make 'n' th subject

n = -34/62

n = - 17/31

Substitute the value into equation (3)

m = 1 - 4(-17/31)/9

m = 1+68/31 ÷9

m = 69/31 × 1/9

m = 69/279

m = 23/93

Hence, the values are n = -17/31 and m = 23/93

Learn more about simultaneous equation here:

https://brainly.com/question/16863577

#SPJ1

PLEASE! I need the prime-power factorizations for these!!!

Answers

Answer:

21) 2 x 11

23) 2 x 2 x 2 x 3

25) 3 x 5

27) 2 x 2 x 5

29) 3 x 7

Step-by-step explanation:

Find 1)
4 integral 0 f(x) dx
if f(x) = 2 for x < 2
= x for x ? 2

Answers

Answer:

X = 1 and below

Step-by-step explanation:

since X is less than 2.

the value of X will be 1 and below.

Could someone please help me?

Answers

[tex]\textit{area of the rectangle}\\\\ A=Lw \begin{cases} L=length\\ w=width\\[-0.5em] \hrulefill\\ L=5\\ w=6 \end{cases}\implies A=(5)(6)\qquad \begin{cases} \textit{tripling the sides}\\[-0.5em] \hrulefill\\ L=3\cdot 5\\ w=3\cdot 6 \end{cases} \\\\\\ A=(3\cdot 5)(3\cdot 6)\implies (3\cdot 3)(5)(6)\implies 9(5)(6)\leftarrow \begin{array}{llll} \textit{new area is 9 times}\\ \textit{the old one}\\ \textit{a ratio of 9 : 1} \end{array}[/tex]

An isosceles triangle has an angle that measures 26°. Which other angles could be in that
isosceles triangle? Choose all that apply.

Answers

Answer:

26° 26° 128°

77° 77° 26°

Step-by-step explanation:

So we have two scenarios here.

One of them is if the base angles are 26°.

If that's true, the other angle is 128°

The other scenario is the opposite.

This means the base angles are 77°

Graph the line that passes through the points (1, -2) and (-1,-6) and
determine the equation of the line.

Answers

Answer:

y = 2x - 4

Step-by-step explanation:

The equation is y = mx + b

m = The slope

b = y-intercept

To find the slope, we look for the rise/run or (y2 - y1) / (x2 - x1)

The slope here is 2, and the y-intercept is located at (0,-4), so the equation is

y = 2x - 4

WILL GIVE BRAINLIEST TO CORRECT ANSWER
In a group of 23 students, 2 study both Art and Biology.

2 study Biology but not Art.

4 study neither subject.

Given that a randomly selected student studies Art, what is the probability the student studies Art and Biology?

Answers

Answer:

Total number of outcomes = 23

number of biology and art students = 2

number of biology students = 2

Since it is given that all the students study art,

number of possible outcomes = 2

probability = number of favorable outcomes/number of total outcomes.

= 2/23

Therefore probability that the selected student studies both art and biology is 2/23.

Type the correct answer in each box. Use numerals instead of words. The length of a rectangular soccer field is 40 feet more than twice the width of the field. Complete an equation for the area of the field, where w is the width of the field.

Answers

A =2 w² +40 w

First Blank =2

Second Blank = 40

Evaluate the following expression: (-5)(6) + (-6) ÷ (-3). Remember to show your work

Answers

Answer:

-28

Step-by-step explanation:

(-5)(6) + (-6) ÷ (-3) =

-30 + (-6) ÷ (-3) =

-30 + 2 =

-28

Hope that helps! :)

-Aphrodite

Answer: =-28

Step-by-step explanation: Hope this help :D

Kelvin and Lewie each design surveys in order to determine the average number of people who buy food at the mall. Kelvin surveys every other person leaving the food area. Lewie surveys every fifth person leaving the mall main entrance. Which set of survey results is most likely to show biased results for people who buy food at the mall

Answers

The set of survey results that is most likely to show biased results for people who buy food at the mall is Lewie's survey.

Lewie's survey samples only every fifth person leaving the mall's main entrance, which means that it only captures a small percentage of the total number of mall visitors. Additionally, by only surveying people leaving the main entrance, Lewie's survey may not capture people who enter and exit the mall through other entrances or exits and may also miss those who don't leave the mall after buying food. As a result, Lewie's survey may not accurately represent the total number of people who buy food at the mall and may lead to biased results.

On the other hand, Kelvin's survey samples every other person leaving the food area. This method captures a larger percentage of the total number of people who buy food at the mall and is more likely to provide a more accurate representation of the total number of people who buy food at the mall.

To learn more about the percentage, visit:

brainly.com/question/29014288

#SPJ4

Answer:

A. Kelvin’s because he surveyed people leaving an area where food is sold

Step-by-step explanation:

What is the degree of the polynomial 7x 3 4x² *?

Answers

The degree of polynomial 7x³ + 4x² is 3 as the highest power is 3.

What is degree of polynomial?

One of the fundamental ideas in mathematics is the degree of polynomials, which determines the maximum number of solutions a function can have and how frequently a function will cross the x-axis on a graph.

Polynomials are also useful in understanding how functions can be represented mathematically. It has the highest exponential power in the polynomial equation.

The greatest power of a variable in a polynomial equation is its degree. When calculating the degree of a polynomial function, only terms with variables are considered. The degree of the polynomial can be determined by looking at the variable term with the highest exponential power.

Learn more about polynomial's degree

https://brainly.com/question/29195568

#SPJ4

Yesterday, Jake ran 2 1/2 miles in 3/5 hour. Lance ran 3 3/4 miles in 5/6 hour. Who ran fastest?

Answers

Answer:

jake did :)

Step-by-step explanation:

hope this helps ! <3

Lance is fastest because the speed of the Lance is 4.5 miles/hour and Jale speed is 4.16 miles/hour as 4.5>4.16

What is a fraction?

Fraction number consists of two parts one is the top of the fraction number which is called the numerator and the second is the bottom of the fraction number which is called the denominator.

Jake ran = [tex]2\frac{1}{2}[/tex] miles = 5/2 miles

In 3/5 hours

Thespeed = (5/2)/(3/5) =  4.16 miles/hours

Lance ran = [tex]3\frac{3}{4}[/tex] miles = 15/4 miles

In 5/6 hours

The speed = (15/4)/(5/6) = 4.5 miles/hours

Thus, Lance is fastest because the speed of the Lance is 4.5 miles/hour and Jale speed is 4.16 miles/hour as 4.5>4.16

Learn more about the fraction here:

brainly.com/question/1301963

#SPJ2

what is the probability that you get a total of 17 given You are playing a version of the roulette game, where the pockets are from 0 to 10 and even numbers are red and odd numbers are black (0 is green). You spin 3 times and add up the values you see. What is the probability that you get a total of 15 given on the first spin you spin a 2

Answers

In  the roulette game, the probability that you get a total of 15 given on the first spin you spin a 2 is 8.26%

To find: the probability that you get a total of 15 in three trials

Given that you spin a 2 on the first trial.

This means, the required probability  is equivalent to the probability of finding a sum of 13 in the next two trials.

In each trial, there are 11 possible outcomes as the pockets numbered from 0 to 10.

so the sample space i.e., the total number of outcomes is:

S = 11^2

S = 121

And the favourable outcomes would be,

(2, 11), (3, 10), (4, 9), (5, 8), (6, 7), (7, 6), (8, 5), (9, 4), (10, 3), (11, 2)

So, the number of favourable outcomes A = 10

Using the definition of probability,

P = A/S

P = 10/121

P = 0.0826

P = 8.26%

Learn more about the probability here:

https://brainly.com/question/15124899

#SPJ4

The complete question is:

You are playing a version of the roulette game, wherethe pockets arefrom 0 to 10 and even numbers are red and odd numbersare black (0 isgreen). You spin 3 times and add up the values yousee. What is theprobability that you get a total of 15 given on thefirst spin youspin a 2

Tamara said the Distributive Property was used to write 21x + 56xy as an equivalent expression, 7(3x + 8y). Is she correct? Explain. And what is the correct expression.

Answers

Answer:

Yes, Tamara is correct that the Distributive Property was used to write 21x + 56xy as an equivalent expression, 7(3x + 8y).

The Distributive Property states that for any real numbers a, b, and c, we have:

a(b + c) = ab + ac

This property allows us to distribute a factor to each term within a set of parentheses.

In this case, Tamara used the Distributive Property to rewrite the expression 21x + 56xy as an equivalent expression. She did this by taking the factor of 7 and distributing it to each term within the parentheses:

7(3x + 8y) = (73x) + (78y) = 21x + 56xy

Therefore, the correct expression is 7(3x + 8y).

Step-by-step explanation:

Tamara is not quite right there. She was on the right track by multiplying the bases by the 7 outside the parentheses. But the “8” base just had a “y” variable attached to it. Tamara put a “xy” variable after she distributed the 7. The correct expression would be 21x+56y.

Live wants to have his birthday party at the bowling alley with a few of his friends but he must be a less than $80 the bowling alley charge a flat fee of $45 for a private party +5.50 per person

Answers

305 because you are supposed to add den x

Answer: 45+16.5=61.5

Step-by-step explanation:

if there is 2 friends going with him it would be  45+16.5=61.5

so that is how much he spends in there is more friends ill give you the other answer if there is more friends

9 people audition for a choir. The choir director must choose one soprano, one alto,
and one tenor.
In how many ways can the director fill these positions?

Answers

The numbers of ways that the director fill these positions is  504 ways.

What is the position about?

There are a few different ways to approach this problem, but one possible method is to use the combination formula.

To fill the position of soprano, the director has 9 choices. After selecting one soprano, the director is left with 8 singers to choose from for the alto position. Then, the director has 7 singers to choose from for the tenor position.

So, the total number of ways the director can fill these positions is:

9 × 8 × 7

= 504 ways.

Alternatively, One can also use the permutation formula to solve the question. The formula of permutation is (n!/(r!(n-r)!)), where n is the total number of items to choose from, and r is the number of items to be chosen.

For this case n is 9, and r is 3, so the permutation would be:

(9!/(3!(9-3)!)

= (987)/(321)

= 504

Therefore, In both cases, the answer is 504 ways.

Learn more about combination formula from

https://brainly.com/question/1587469

#SPJ1

How do you graph a parent graph?

Answers

This is how you construct a parent graph - it is the simplest form of the function, and has a basic shape.

The most basic form of a function is a parent function. Its essential shape is not changed in any manner. In mathematics, some graphs are frequently seen. Because of this, the graphs of quadratic functions, square roots, absolute values, cubics, and cube roots are among the original, widespread functions that are referred to as parent graphs.

For instance, you should still be able to identify the parabola that has undergone various transformations when you view a u-shaped graph that has been inverted and stretched vertically.

We can take a few examples to understand this concept further.

For a quadratic equation, the parent graph is [tex]f(x) = x^{2}[/tex], which is a parabola. For a cubic equation, the parent graph is [tex]f(x) = x^{3}[/tex].

Hence, this is how you construct a parent graph - it is the simplest form of the function, and has a basic shape.

To learn more about parent graphs, visit the link:

brainly.com/question/20333814

#SPJ4

Find the x and y Intercept of x + 2y = -14

Answers

Answer:

Y-intercept: (0, -7)

X-intercept: (-14,0)

Step-by-step explanation:

To find the y-intercept, we need to put 0 in for x

0 + 2y = -14

2y = -14

y = -7

So, the y-intercept is located at (0, -7)

To find the x-intercept, we need to put 0 in for y

x + 2(0) = -14

x = -14

So, the x-intercept is located at (-14,0)

Step-by-step explanation:

To find the y-intercep, we need to put 0 in for x

0 + 2y= -14

2y = -14

y = - 7

So, the y - intercept is located at ( 0, - 7)

In a random sample of 70 people, it was found that 44 of them were fans of the New York Yankees. What is the margin of error for the true proportion of all individuals who are fans of the New York Yankees? A. 0.0088 B. 0.058 C. 0.063 D. 0.116 E. 0.173

Answers

The margin of error for the true proportion of all individuals who are fans of the New York Yankees is 0.058.

The Correct option is (B).

How to find the margin of error?

The formula to calculate the margin of error  for the true proportion is;

M = √[p(1 - p)/n]

Given:

n= 40

p = 44/70

Now, The general formula for the margin of error would be:

z x √[p (1-p) ÷ n]

where:

z = values for selected confidence level

p = sample proportion

n = sample size

Since the confidence level is not given,

√[p (1-p) ÷ n]  

=√[44/70 (1 - (44/70) ÷ 70]

=√[0.6286 (0.3714)] ÷ 70

=√0.2335 ÷ 70

= √0.0033357

= 0.05775 or 0.058

Learn more about Margin Error here:

brainly.com/question/10218601

#SPJ1

3 chairs and 4 tables cost rs 7540. if the price of a chair is 220 find the price of table?

ans - 7120

Answers

Answer:

The price of a table is rs1720

Step-by-step explanation:

Let C and T be the individual prices of the tables and chairs.

We know that 3C + 4T = rs7540

We are then told that C = rs220, so we can enter that into the equation to find T:

3C + 4T = rs7540  

3(220) + 4T = rs7540  [for C = rs220]

660 + 4T = 7540

4T = rs6880

T = rs1720

Check:

Do 3 chairs at 220 each and 4 tables at 1720 each add to a total of 7540?

Chairs:   rs660

Tables:  rs6880

Total = rs7540  YES

Solve these problems

A= 12+4×2-7
B= 2×(-3)+8

Answers

A=13
B=2

You have to calculate the multiplication first

Answer:

A. 13

B. 2

Step-by-step explanation:

You use order of operations.

A. 4x2=8+12=20-7=13

B. 2x-3=-6+8=2

what is -5.6 opposite ?​

Answers

Answer: 5.6

Step-by-step explanation:

the opposite of an negative number...

So your answer would be....

        =5.6

Answer:

[tex]5.6[/tex] or [tex]\dfrac{1}{-5.6}[/tex]

Step-by-step explanation:

The additive inverse of [tex]-5.6[/tex] is [tex]-1 \cdot -5.6 = \boxed{5.6}[/tex]

or...

If you mean the multiplicative inverse of  [tex]-5.6[/tex], then the answer would be [tex]\dfrac{1}{-5.6}[/tex]

the scatter plot shows a regression line of units demanded and price. if the demand is for 35 units what would be the predicted price per unit?
A)$20
B)$23
C)$27
D)$32

Answers

According to the following graph, we have identified that if the demand is for 35 units then the predicted price per unit is $27.

The term graph in math is defined as pictorial representation of algebraic equation.

Here we have given the following graph and here  we also know that the scatter plot shows a regression line of units demanded and price.

Here we need to know the definition of regression line, which means the relationship between two variables. And it is applied in scenarios where the change in the value of the independent variable causes changes in the value of the dependent variable.

Based on these definition, here we have the relationship between the units demanded and the price of those units.

Now, by looking into the given graph, we have identified that if the demand is for 35 units, then the units price is $27.

Therefore, option (c) is correct.

To know more about Graph here

https://brainly.com/question/17267403

#SPJ4

Here are several function rules. Calculate the output for rules 1–5 when you use -6 as the input for each rule. Simplify fractions and express in the form a/b if necessary and use the word pi for π
.

Answers

Answer: 13,36,-2,-2,pi

Step-by-step explanation:

You do exactly what it says for the rule to -6 to get your answer.

road to white house Math

Answers

The value of f(4) - g(-5) if function  f(x) = 3 / 2x + 2 and g(x) = 2x² - 3 is -39.

What is function?

An expression, rule, or law in mathematics that specifies the relationship between an independent variable and a dependent variable (the dependent variable). In mathematics and the sciences, functions are fundamental for constructing physical relationships.

Given:

f(x) = 3 / 2x + 2 and g(x) = 2x² - 3

Calculate the value of f(4) and g(-5) as shown below,

f(4) = 3 / 2 × 4 + 2

f(4) = 12 / 2 + 2

f(4) = 6 + 2

f(4) = 8

g(-5) = 2 × (-5)² - 3

g(-5) = 2 × 25 - 3

g(-5) = 50 - 3

g(-5) = 47

Now, calculate the value of f(4) - g(-5) as shown below,

f(4) - g(-5) = 8 - 47

f(4) - g(-5) = -39

Thus, the value of f(4) - g(-5) is -39.

To know more about function:

https://brainly.com/question/5975436

#SPJ1

Does anyone know the question to this ?? :(

Answers

Answer:

The ratio of the new area to the old area will be 16:1

Step-by-step explanation:

I remember learning this in class. The radius is quadrupled, which means the radius is 4 times bigger. This will make the new area 16 times bigger than the old area.

Let's check

Area of circle: 3.14 x r^2

Area of the circle when radius 6:

3.14 (6)^2 = 113.04 ft^2

Area of the new circle when the radius is quadrupled:

3.14 (24)^2 = 1808.64 ft^2

1808.64 divided by 113.04 = 16

So, the ratio of the new area to the old area will be 16:1

Brian sat in a massage chair at a shopping mall for 8 minutes and paid $9. Norah sat in
the same massage chair for 12 minutes and paid $11. If the relationship between the
number of minutes and the amount paid is linear, with x representing the minutes and y
representing the amount paid in dollars, which of these equations models the situation?
A. x = 0.5y + 5
B. x = y + 1
C. y = 0.5x + 5
D. y = x + 1

Answers

Answer:

(1/2)x + $5 (Answer A)

Step-by-step explanation:

Two points on the line representing the cost are (8, $9) and (12, $11).

The change in x is 4 (minutes); this is the 'run.'  The change in y is $2 (this is the 'rise').  Thus, the slope of this line is m = rise / run = $2/(4 min), or 1/2 dollar per min.

Applying the slope-intercept formula y = mx + b, we get:

$9 = (1/2)(8) + b, and from this we see that b must be $5.

Then the correct equation is y = (1/2)x + $5.

The table below shows information about how many fans there were at two
football matches in a local tournament.
What is the difference between the number of away fans at the semi-final and at
the final?
Semi-final
Final
Total number of fans
250
400
Ratio of home fans
to away fans
6:4
7:3

Answers

Therefore , the solution of the given problem of ratio is Because of this, at a 95% confidence level, (a,b) = ($65.57, $74.43).

What is ratio?

A ratio or fraction in math displays how many times one number is contained in another. For instance, the proportion of oranges to lemons in a bowl of fruit is eight to six if there are eight oranges and six lemons (that is, 8:6, which is equivalent to the ratio 4:3 or decimal 1.333).

Here,

Confidence intervals are defined as a range of values with a known chance that a parameter's value falls inside them.

A statistical data's confidence interval can be expressed as.

=> x+/-zr/√n

=> Knowing that;

Average Sample x = $70.00

$17.50 is the standard deviation.

n = 60 samples were used.

95% confidence interval

95% confidence interval for z = 1.96

substituting our current values;

$70.00+/-1.96($17.50/√60)

$70.00+/-1.96($2.259240285287)

$70.00+/-$4.428110959163

$70.00+/-$4.43

= ( $65.57, $74.43)

Therefore , the solution of the given problem of ratio is Because of this, at a 95% confidence level, (a,b) = ($65.57, $74.43).

To know more about ratio , visit

https://brainly.com/question/13419413

#SPJ1

Factor quadratic trinomials
2x^2+7x+6
3x^2+5x+2

With method X pleaseee:(

Answers

The first thing to do is look at the left hand side and factorise it. To do this we use the reverse of FOIL. Then when the expression is factorised, we can solve for x.

1. First find the skeleton with just x's:

(2x )(x )

2. Next, find 2 numbers that mutiply to make 6, and these go at the end of the brackets. This could be 6 and 1 or 2 and 3, or -6 and -1 or -2 and -3.

Since there is a 7x term, the 2 numbers must add to 7 when one of them is multiplied by 2 - due to the 2x term (2x ).

so (2x 3)(x 2) or (2x 2)( 3)

3. Trial and error shows us that (2x + 3)(x + 2) is the right answer.

4. Now set each bracket respectively to 0 and solve for x. The solutions are x = -3/2 and x = -2.

And there we have the answers!
Other Questions
If 467.08 grams of Oz are reacted, how many grams of C6H5CH3 will also be reacted? Why was xenia important in Greek society? An object has a density of 3.25 kg/m?. If it has a total volume of 12.65m?. What is the object's mass? Corn seeds with identical genetic information were planted on two adjacent farms. The corn plants on one farm were well fertilized and grew large, while the plants on the other farm were not given fertilizer and did not grow as large. The best explanation for these observations is that Ivan's initial response to seeing the series numbers of his wife's ticket in the paper is to be angry. the lotterry ticket true or false What can be known about Mendel's? What best demonstrates the Iroquois view of women? 6. Jenna wants to hang outdoor stringed lights on her house along the roof line and horizontally across, connecting the ends of the roof line to create a triangle. What is the approximate length, in feet, of lights that she needs to create one triangle? A. 48 B. 64 C. 80 D. 98 Your friend recommends that you visualize as you read. What is she talking about? She means you should take lots of breaks when you read. She thinks you should try to see the story in your mind as you read it. You're good at sounding out wordseven words you have not seen before. She wants you to tell her what happened in the first few chapters. Explain how oil prices in the United States could be affected if the checkpoints in Asia and Africa were blocked. HELPPP This incident reminded the poet that we should let go of cares and worries. Things of the heart we should hang on to, however. What might those be?The poem is Wild Grapes by Robert Frost evaluate 27/32 16/27, give your answer in its simplest form Write a word or phrase that has the same meaning as the term given,(gunpowder) Read the details from zombies on the loose and a zombies confession how is the description of the zombies in the story diffrent from the zombies description of itself in the poem a/the poem zombie thinks its friendly b/the poem zombie moans and groans c/the poem zombie has a poor memory d/the poem zombie has outstretched arms 20 pts A Raisin in the Sun essay sum of -7g and 4g+2 Translate and solve: -5 times b is no less than 35. Note: Write your solution in interval notation, The importance of Information systems in hospitality industry? Why do periods stop when you get old I need a detailed paragraph bc I have a test TOMMORROW and Im freaking the hell out ONLY GIVING BRAINLYEST IF YOU ANWSER QUICKLY AND CORRECTLYA teacher asks her students to write down all they eat in a day and then calculate the total number of calories consumed. aExperiment bInvestigation cTechnology development