Take 20 laps divide by 8 then take the number times 9 laps
The answer is the first page, first graph
Answer:
4.4% of the population with IQ between 120 and 125.
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 100
Standard Deviation, σ = 15
We are given that the distribution of IQ scores is a bell shaped distribution that is a normal distribution.
a) Let X be a person's IQ score.
Then, density functions for IQ scores is given by:

b) P(population with IQ between 120 and 125.)
Formula:



12x - 8y = -12
6x + 4y = -30
Multiply the 2nd equation by 2, to make the Y coefficients opposite:
6x + 4y = -30 x 2 = 12x + 8y = -60
Now add the two equations:
12x -8y = -12 + 12x +8y = -60
= 24x = -72
Divide bothe sides by 24 to solve for x:
x = -72/24
x = -3
Now replace x with -3 in the first equation to solve for y:
12(-3) - 8y = -12
-36 - 8y = -12
Add 36 to each side:
-8y = 24
Divide both sides by -8 to solve for y:
y = 24 / -8
y = -3
X = -3 and y = -3
(-3,-3)