Help please(work provided)

If [tex]X,Y[/tex] are independent, we have the properties for expectation and variance,

[tex]\Bbb E[aX + bY] = a\,\Bbb E[X] + b\,\Bbb E[Y][/tex]

[tex]\Bbb V[aX + bY] = a^2\,\Bbb V[X] + b^2\,\Bbb V[Y][/tex]

where [tex]a,b\in\Bbb R[/tex] are fixed.

Then

[tex]\Bbb E[R - S] = \Bbb E[R] - \Bbb E[S] = 10 - 7 = \boxed{3}[/tex]

and

[tex]\Bbb V[R - S] = \Bbb V[R] + (-1)^2\, \Bbb V[S] = 4^2 + 3^2 = \boxed{5}\,{}^2 = 25[/tex]

(recall that standard deviation = √(variance))

Answer:

B 55x + 65 = 296; x = 4.2 hours

Step-by-step explanation:

The equation to determine the number of hours worked by the plumber is 65 + 55x = 296.

The number of hours worked by the plumber is 4.2

Option B is the correct answer.

An equation is a mathematical statement that is made up of two expressions connected by an equal sign.

We have,

Charges for home visit = $65

Charges for each hour = $55

Let the number of hours = x

Total charges = $296

We can make an equation:

65 + 55x = 296

The number of hours can be calculated.

65 + 55x = 296

Subtracting 65 on both sides.

65 + 55x - 65 = 296 - 65

55x = 231

Dividing both sides by 55.

x = 231 / 55

x = 4.2

Thus,

The equation to determine the number of hours worked by the plumber is 65 + 55x = 296.

The number of hours worked by the plumber is 4.2

Option B is the correct answer.

Learn more about equations here:

https://brainly.com/question/14686792

#SPJ2

Answer:

Given that y varies proportionally with  x , with a constant of proportionality k=13 , find y when x=12 .

Write the equation of the proportional relationship.

The variable x varies proportionally with y with a constant of proportionality equal to 13

So,

Substitute the given x value.

Step-by-step explanation:

[tex]{ \qquad\qquad\huge\underline{{\sf Answer}}} [/tex]

lets solve ~

[tex]\qquad \sf  \dashrightarrow \: 3 \sqrt{50} \times \sqrt{22} [/tex]

[tex]\qquad \sf  \dashrightarrow \: 3 \sqrt{2 \times 5 \times 5} \times \sqrt{2 \times 11} [/tex]

[tex]\qquad \sf  \dashrightarrow \: 3 \sqrt{2 \times 2 \times 5 \times 5 \times 11} [/tex]

[tex]\qquad \sf  \dashrightarrow \: 3 \times 2 \times 5 \times \sqrt{11} [/tex]

[tex]\qquad \sf  \dashrightarrow \: 30 \sqrt{11} [/tex]

Answer:

330-339

jakjss

js

sk

am

am

am

a

ma

ma

am

67

Using proportions, the equation in terms of Tim is given by:

T(t) = 17t.

A proportion is a fraction of a total amount, and the measures are related using a rule of three. Due to this, relations between variables, either direct(when both increase or both decrease) or inverse proportional(when one increases and the other decreases, or vice versa), can be built to find the desired measures in the problem, or equations to find these measures.

For this problem, we have that:

Hence the total amount, as a function of Isaac's amount, is given by:

T(t) = I + H + t

T(t) = 4t + 12t + t

T(t) = 17t.

More can be learned about proportions at https://brainly.com/question/24372153

#SPJ1

Answer:

Step-by-step explanation:

Answer: 11.4

Step-by-step explanation:

The temperature drop is B. 3.968 degrees each hour.

The temperature drop per hour can be computed by dividing the total temperature drop by the number of hours over which the temperature dropped.

The total steady drop in temperature = 24.8 degrees

Total number of hours for the temperature drop = 6¹/₄ hours

6¹/₄ hours = 6.25 hours

Temperature drop per hour = total drop/total hours of drop

= 2(4.8 ÷ 6¹/₄ hours)

= 3.968 degrees

Thus, the temperature drop is B. 3.968 degrees each hour.

Learn more about temperature drops at https://brainly.com/question/15383031

#SPJ1

The system of linear inequalities is represented by the graph is y > x – 2 and y < x + 1.

A statement of an order relationship-greater than, greater than or equal to, less than, less than or equal to- between two numbers or algebraic equations.

The given options are,

y > x – 2 and y < x + 1

y < x – 2 and y > x + 1

y < x – 2 and y > x + 1

y > x – 2 and y < x + 1

Since,

The linear equation of a straight line is

y = mx + c,

where m is the gradient or slope, and

y = c is the value where the line cuts the y-axis.

The formula for slope of line with points (x1,y1) and (x2,y2) can be expressed as,

m = (y2 - y1) / (x2 - x1)

Now from y > x – 2 and y < x + 1

the first line passes through (0, 1) and (0, -1)

So,slope m = (0 - 1) / (0 - 1)

⇒ m = 1

Now the line intercept y-axis at (1, 1)

So, c = 1

So,equation of line is given as,

y < x + 1

the second line passes through (0, 2) and (0, -2)

So,slope m = (0 - 2) / (0 - 2)

⇒ m = 1

Now the line intercept y-axis at (-2, 0)

So, c = -2

So,equation of line is given as,

y < x - 2

So, we get y > x – 2 and y < x + 1.

Thus, the system of linear inequalities is represented by the graph is y > x – 2 and y < x + 1.

To learn more about inequality :

https://brainly.com/question/13363104

#SPJ1

The missing graph of the question is attached.

Answer:

p = independent

t = dependent

The amount of hired truckers will depend on the amount of produce that has to be shipped from California to New York.

Hope this helps :)

Answer: £1342.5

Step-by-step explanation:

y = a(1 + R)^n

y = 1290(1 + 0.005)^8

y ≈ 1342.51

∴ £1342.5

Step-by-step explanation: They are word problems into equations. Have a good night. you will get them right.

7.) x - 20 = -8

8.) x/6 = 240

9.) - 1000 + x = 8

10.) x/20 = 8

The probability that the ace of diamonds and a black card will come is 1 / 51 .

Case A :

probability of first getting an ace of diamonds = 1 / 52

probability of getting a black card given first card is ace of diamond = 26 / 51

Hence , probability that the ace of diamonds and a black card will come is  ( 1 / 52 ) * ( 26 / 51 ) = ( 1 / 102 )

Case B :

probability of first getting a black card = ( 26 / 52 )

probability of getting an ace , given first card is a black card = ( 1 / 51 )

Hence , the probability that the ace of diamonds and a black card will come is  ( 26 / 52 ) * ( 1 / 51 ) = ( 1 / 102 )

P ( A ∪ B ) = P ( A ) + P (B ) + P ( A ∩ B )

                  = ( 1 / 102 ) + ( 1 / 102 )

                = 1 / 51 .

To learn more on probability go to :

https://brainly.com/question/24756209

#SPJ4

Answer:

1. domain: -6 ≤ x ≤ 7

range: -6 ≤ y ≤ 4

2. domain: 5 > x

range: -5 < y

Step-by-step explanation:

1. domain: the farthest number left that the line reaches is -6, while the farthest right is 7. due to the line being closed as well as the points being filled in, you use the less than or equal to sign.

range: the farthest number down that the line reaches is -6, while the farthest is goes up is 4. again, since the points are filled in, you use the "or equal to" sign.

2. domain: since the only plotted point is 5, and the point is not filled in, you would say that 5 is greater than x due to the direction that the line moves

range: the lowest part of the line touches -5 and only goes up from there, therefore y is greater than -5

Answer:

x = 20/3

you will need 20/3 of the 60% solution

Step-by-step explanation:

0.25(40) + 0.60x = 0.30(x + 40)

10 + 0.60x = 0.30x + 12

0.30x = 2

Not sure if it's right

-4x < or = to -1 and x > or = 1/4

Explation

Answer: 2 ≤ x < 7

Step-by-step explanation:

10 ≤ 3x + 4 < 25  ==> solve for x, so work to isolate the x variable

10-4 ≤ 3x + 4-4 < 25-4

6 ≤ 3x < 21

6/3 ≤ 3x/3 < 21/3

2 ≤ x < 7

Answer:

I believe it's [2, 7). It has to be solve differently.

Using the addition of all the exercise, Javier runs on the treadmill on Monday is 0.40 hours.

Addition is one of the mathematical operations. The addition of two numbers results in the total amount of the combined value.

Given that Javier completed 3 repetitions of each exercise. thus by multiplication time taken by Javier to complete each exercise is as follows;

Squats = 0.8 x 3= 0.24 hour

Crunches = 0.03 x 3 = 0.09 hour

Lunges = 0.04 x 3 = 0.12 hour

curls = 0.05 x 3 = 0.15 hour

we can calculate the total time taken to complete all exercises as;

0.24 + 0.09 + 0.12 + 0.15

= 0.60 hour

Now the time took on treadmill by Javier;

1 hour - 0.60 hour

0.40 hour

Hence,  If he completed 3 repetitions of each exercise, then he run 0.40 hours on the treadmill on Monday.

Read more about Addition here:

brainly.com/question/20658817

#SPJ1

The length of the arc for the given circle is 24cm.

Given:

To find: Length of the arc.

Finding:

On substituting the values of r and Θ in the formula of length of the arc, we get:

L = 4(6) = 24 cm.

Hence, the length of the arc for the given circle is 24cm.

To learn more about the length of an arc, refer to the link:https://brainly.com/question/2005046

#SPJ4

Sample space when a coin is tossed is {H, T}

Sample space for drawing a card is {1, 2, 3, 4}

Sample space = {H1, H2, H3, H4, T1, T2, T3, T4}

Event that the coin toss is tails = {H1, H2, H3, H4}

The sample space describing all possible outcomes are (H1, H2, H3, H4, T1, T2, T3, T4).

A series of independent Bernoulli trials with a chance of 1/2 on each trial is referred to as a fair coin in probability theory and statistics. A biased or unjust coin is one for which the probability is not equal to one-half.

The presumption that a coin is fair is sometimes made by making reference to an ideal coin in theoretical investigations. When John Edmund Kerrich experimented with flipping coins, he discovered that 679 times out of 1000, a coin fashioned of a wooden disc the size of a crown that was coated with lead on one side landed heads (wooden side up).

To learn more about the fair coin, Visit:

https://brainly.com/question/1360418

#SPJ4

The increment in the percentage of dessert sales will be 25%.

The quantity of anything is stated as though it were a fraction of a hundred. A quarter of 100 can be used to express the ratio. Per 100 is what the term percent signifies. The symbol ‘%’ is used to symbolize it.

The percentage is given as,

Percentage (P) = [Final value - Initial value] / Initial value x 100

I was able to sell 1,200 desserts throughout the month of January. Your dessert sales jumped to 1,500 in February.

Then the increment in the percentage will be given as,

P = [(1500 - 1200) / 1200] x 100

P = (300 / 1200) x 100

P = 0.25 x 100

P = 25%

The increment in the percentage of dessert sales will be 25%.

More about the percentage link is given below.

https://brainly.com/question/8011401

#SPJ1

Answer:

E

Step-by-step explanation:

You already know that TS = AB and TU = BC because it shows that in the images using the tick marks. SSS Triangle Congruence Postulate is when two triangles are congruent to each other because all the corresponding side lengths are equal to each other. So we already have two side lengths that are equal to each other, and, in order for SSS to be true, we need all 3 side lengths to be equal to each other. The only two side lengths not equal to each other yet are US and CA so if those were to be equal to each other, all corresponding side lengths would be equal to each other.

Let me know if you have any questions.

The expression for the total number of miles Pablo drove in the two weeks is (115+k) miles.

In mathematics, an expression is defined as a set of numbers, variables, and mathematical operations formed according to rules dependent on the context.

Given that Last week, Pablo drove 115 miles. This week, he drove k miles. Therefore, the total number of miles for which Pablo drove can be written as,

Total number of miles = Number of miles last week + Number of miles this week

                                    = 115 miles + k miles

                                    = (115 + k) miles

Hence, the expression for the total number of miles Pablo drove in the two weeks is (115+k) miles.

Learn more about Expression here:

https://brainly.com/question/13947055

#SPJ1

Using scientific notation , the electricity used in 1950 was 7.131 × 10¹ times more than that used in 1902 .

Values that are either too huge or too little to be conveniently expressed in decimal form can be expressed using scientific notation (typically would result in a long string of digits). It is also referred to as scientific form, standard index form, and standard form in the UK. This base ten notation is often used by scientists, mathematicians, and engineers because it can make various mathematical procedures easier.

One can represent exceedingly large or extremely small quantities using scientific notation. In scientific notation, the result of multiplying an integer between 1 and 10 by a power of 10 is written. For instance, in scientific notation, 35,000,000 can be written as 3.5× 10⁷.

Given that the use of electricity in the US in 1902 was 6.03 x 10⁹kilowatt-hours and the use of electricity in the US in 1950 was 4.3 x 10¹¹ kilowatt-hours.

These are both represented in scientific notation.

Now we have to divide to find the number of times more electricity is used.

(4.3 x 10¹¹) ÷ (6.03 x 10⁹)

= 71.31011...

≈ 7.131 × 10¹

Hence the scientific representation is given by 7.131 × 10¹ times.

To learn more about scientific notation visit:

https://brainly.com/question/18073768

#SPJ1

Answer:

I'm assuming the double minus marks meant 5 and 6 were negative. Answer is 30.

Step-by-step explanation:

[tex]17+\abs(-12--5)-(-6)\\17+\abs(-12+5)-(-6)\\17+\abs(-7)-(-6)\\17+7-(-6)\\17+7--6\\24--6\\24+6\\30[/tex]

Answer:The answer would be 28

Step-by-step explanation:17-6 is 11

                                            The absolute value of -12-5 is 17

                                               17+11=28

                                            So therefore the answer would be 28.

Answer:

The greatest common factor of 44 and 22 is 22.

Step-by-step explanation:

First, you should list all the factors of 44 and 22. For 44, the factors are: 1, 2, 4, 11, 22 and 44

For 22, the factors are: 1, 2, 11 and 22

The greatest common factor is 22.

Answer: 22

Step-by-step explanation:

In order to find GCF of 44 and 22, take the prime factorization of the two numbers

22: 11*2

44: 11*4=11*2*2

Notice they both have 11*2 in their prime factorization.

11*2=22

GCF of 44 and 22 is 22

x ≤ 2  but must be greater than 0 .  triangles are the possible lengths of the remaining side.

How is an isosceles triangle defined?

The length of one of the congruent side is 5

The total length of two congruent sides is 10

Perimeter at the most is 12 (meaning the maximum length of perimeter is 12)

The third side of the triangle must be 12-10 = 2 at the most

Writing this requirement as inequality we have

x ≤ 2  but must be greater than 0

Learn more about isosceles triangle

brainly.com/question/2456591

#SPJ9