Question

A manufacturer knows that their items have a lengths that are approximately normally distributed, with a mean of 5.7 inches, and standard deviation of 1.4 inches.

If 36 items are chosen at random, what is the probability that their mean length is greater than 5.5 inches?

According to a survey, 10% of Americans are afraid to fly. Suppose 1100 Americans are sampled.

a) What is the probability that 121 or more americans in the survey are afraid to fly? Write your answer as a percentage rounded to two decimal places.

b) What is the probability that 165 or more americans in the survey are afraid to fly? Write your answer as a percentage rounded to two decimal places.

c) What is the probability that 8% or less of the americans surveyed answered they were afraid to fly? Write your answer as a percentage rounded to two decimal places.

Answer 1