Twenty-five percent of all automobiles undergoing an emissions inspection at a certain inspection station fail the inspection.

(d) What is the probability that among 25 randomly selected cars, the number that pass is within 1 standard deviation of the mean value?

Guest Apr 11, 2017

#1**+1 **

Twenty-five percent of all automobiles undergoing an emissions inspection at a certain inspection station fail the inspection.

(d) What is the probability that among 25 randomly selected cars, the number that pass is within 1 standard deviation of the mean value?

I think this is a trick question.....

The number that are within 1 standard deviation of the mean in a normal distribution, which I think is assumed here, is always 68%

Melody
Apr 11, 2017

#2**+1 **

"*Twenty-five percent of all automobiles undergoing an emissions inspection at a certain inspection station fail the inspection. *

*(d) What is the probability that among 25 randomly selected cars, the number that pass is within 1 standard deviation of the mean value?*"

I've assumed a binomial distribution. i.e. each car either passes or fails.

.

Alan
Apr 11, 2017