Please help me with this question!

Answer:

(72.5,87.5)

Step-by-step explanation:

The interval of times that represents the middle 99.7% of his finishing times in the 400 meter race is; (73.5, 87.5)

We are given;

Mean; E(X) = μ = 80 seconds

Standard Deviation; σ = 2.5

From the empirical rule, the probability of obtaining values within one deviation from the mean is 0.68; within two deviations is 0.95 and within 3 deviations from the mean is 0.997.

We have 99.7 % of the values within 3 deviations from the mean in our question and so the intervals are;

μ - 3σ = 80 - 3(2.5) = 73.5

μ + 3σ = 80 + 3(2.5) = 87.5

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Answer:

158

Step-by-step explanation:

If the average rate between August and October was on an increase, then November sales will be 158.

This is defined as the quantity or amount of something which is measured per unit of something else.

From the stock list, the average rate kept increasing which means option D is the most appropriate choice.

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Answer:

D is the answer

Step-by-step explanation:

Hope that helps

Answer:

it is the first one because you would be deciding by 2

Answer:

d= 2√a/π

To calculate the diameter, rewrite the formula to isolate D

Because a negative diameter doesn’t make sense, eliminate the negative answer from the solution

Simplify further to get the solution

The formula to calculate the diameter of the circle is d = 2 √( A/π )

where d = diameter of the circle

A = area of the circle

What is a Circle?

A circle is a closed two-dimensional figure in which the set of all the points in the plane is equidistant from a given point called “center”. Every line that passes through the circle forms the line of reflection symmetry. Also, the circle has rotational symmetry around the center for every angle

The perimeter of circle = 2πr

The area of the circle = πr²

where r is the radius of the circle

The standard form of a circle is

( x - h )² + ( y - k )² = r²,

where r is the radius of the circle and (h,k) is the center of the circle

Given data ,

Let the radius of the circle be = r

So , the diameter of the circle = 2r

Now , the area of the circle = πr²

Substituting the value for r , we get

Area of the circle = ( 1/4 ) πd²

So , A = ( 1/4 ) πd²

Now , solving the equation for diameter of circle d , we get

Multiply by 4 on both sides of the equation , we get

πd² = 4A

Divide by π on both sides of the equation , we get

d² = 4A/π

Taking square roots on both sides of the equation , we get

d = 2 √A/π

Therefore , the value of d is 2 √A/π

Hence ,

The formula to calculate the diameter of the circle is d = 2 √( A/π )

where d = diameter of the circle

A = area of the circle

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Answer:

X= -5

Step-by-step explanation:

Good luck!

Answer:

X=-5

Step-by-step explanation:

100 + 84 - 62x =494

184 - 62x =494

494-184 = -62x

310 =-62x

310/-62 =x

X= -5

1. 10 1/2

2. 120

3. 12

Hope this helps =]

directly varies for that mean if y increases x will increase too and the other way around if y decreases x will decrease too.

an easy way to solve this is to make all values into fraction ik it sounds confusing lemme explain it. so if we say [tex]\frac{x}{y}[/tex] and add the values of the known [tex]\frac{3}{9}[/tex] we can say that if [tex]\frac{x}{15}[/tex] is equal to [tex]\frac{3}{9}[/tex]

now we just solve it for x

[tex]\frac{x}{15} = \frac{3}{9} \\9x = 45\\x= 5[/tex]

hence when y is 15 x will be 5

Answer:

D is correct

Step-by-step explanation:

i did it

Answer: 4

Step-by-step explanation:

First we need to find the difference of the balance.

it was -80 then it became -44. The difference is 36.

Next we divide 36 by 9 from the 9 parents.

The answer is 4

Answer:

D. No, because group A is already the control group.

Answer:

i think 6 because it has 3 rows and 2 columns that's 3 rows with 2 elements and that equals up to 6 hope that help

Answer:

The area is 256

Step-by-step explanation:

she forgot to square her scale factor because that's how you do it for area

Answer:

256

hope it helps

please mark brain list

Answer:

x = 5

Step-by-step explanation:

x² + (2x+2)² = (2x+3)²

x² + 4x² + 8x + 4 = 4x² + 12x + 9

x² - 4x - 5 = 0

(x - 5)(x + 1) = 0

x = -1  This can be discounted as the answer because you cannot have a negative length

answer: x = 5

Answer:

4

Step-by-step explanation:

Sum and Divide

The answer is letter C. (1/2)

Answer:

C. [tex]\frac{1}{2}[/tex]

Step-by-step explanation:

Hope this helps!

Answer:

4

Step-by-step explanation:

Line f is 4 units from the x-axis.

Answer:

i think 1996 but i don't know if your adding subtracting but i add and i got 1996

Answer:

192

Step-by-step explanation:

This is because its a square and all the sides on a square are equal so it would be:

top/bottom= 8*8

left/ right= 8*8

front/ back= 8*8

all equal 64 then you do 64*64*64 to get 192!

Hope this helped!

Answer:

i tried

Step-by-step explanation:

im suppose to be gifted... it took me 20 minutes and im in 9th grade RIP, but is it 9??