Question: The breaking strength of plastic bags used for packaging produce is normally distributed, with a mean of 5 pounds per square inch and a standard deviation of 1.5 pounds per square inch. What proportion of the bags have a breaking strength of
a. less than 3.17 pounds per square inch?
b. at least 3.6 pounds per square inch?
c. between 5 and 5.5 pounds per square inch?
d. 95% of the breaking strengths will be contained between what two values symmetrically distributed around the mean?