11) The length of time it takes college students to find a parking spot in the library
parking lot follows a normal distribution with a mean of 3.5 minutes and a standard
deviation of 1 minute. Find the cut-off time which 75.8% of the college students exceed
when trying to find a parking spot in the library parking lot.

This is a poorly worded question, so you’ll have to use your own judgment about
which answer to use here.
3.8
4.3
4.0
4.2
12) The amount of soda a dispensing machine pours into a 12 ounce can of soda follows
a normal distribution with a standard deviation of 0.24 ounce. Every can that has more
than 12.60 ounces of soda poured into it causes a spill and the can needs to go through a
special cleaning process before it can be sold. What is the mean amount of soda the
machine should dispense if the company wants to limit the percentage that need to be
cleaned because of spillage to 3%?

13) The tread life of a particular brand of tire is a random variable best described by a
normal distribution with a mean of 60,000 miles and a standard deviation of 1200 miles.
What warranty should the company use if they want 96% of the tires to outlast the
warranty?

14) Use a normal probability plot to asses whether the sample data could have come from
a population that is normally distributed.
An industrial psychologist conducted an experiment in which 40 employees that were
identified as "chronically tardy" by their managers were divided into two groups of size
20. Group 1 participated in the new "It's Great to be Awake!" program, while Group 2
had their pay pay docked. The following data represent the number of minutes that
employees in Group 1 were late for work after participating in the program.
not normally distributed
normally distributed
15) Use a normal probability plot to asses whether the sample data could have come from
a population that is normally distributed.
The following data represent a random sample of the number of shares of a
pharmaceutical company's stock traded for 20 days in 2000.
normally distributed
not normally distributed