Use the Empirical Rule to answer each question.

Question

During 1 week an overnight delivery company found that the weights of its parcels were normally distributed, with a mean of 16 ounces and a standard deviation of 4 ounces.
(a) What percent of the parcels weighed between 8 ounces and 20 ounces? (Round your answer to one decimal place.)

(b) What percent of the parcels weighed more than 28 ounces? (Round your answer to two decimal places.)

Answer 1

8 = µ-2σ
20 = µ+1σ
So what does your Z table say?

Answer 2

A. 13.5% + 34% + 34%
= 81.5%
B. (100% - 99.7%) / 2
=0.15%