Question

Assume production time per unit is normally distributed with a mean 40 minutes and standard deviation 8 minutes. Using the empirical rule, what percent of the units are produced in MORE than 32 minutes?

Answer 1

84%

Explanation:

We find the z-score here

z= x-mean/SD = 32-40/8 = -1

So the probability we want to find is;

P(z>-1)

This can be obtained using the standard score table

P(z>-1) = 0.84 = 84%