Question

X~ (23.5,6.64) what is the probability that the speed of a car is at most 29mph

Answer 1

Answer: 0.7995 or 79.95%

Given:

X~N(23.4, 6.64)

Where:

mean = 23.4

standard deviation = 6.64

First, let us find the z-score using the formula:

$z=\frac{x-\mu}{\sigma}$$z=\frac{29-23.4}{6.64}=0.84$

Now, we need to look at the table and find the value of 0.8 under 0.04.

And here, we get .7995.

Therefore, the probability that the speed of a car is at most 29 is 0.7995 or 79.95%