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Quiz #3 STA2023
sample proportion sampling distributions
Provide all of your answers/explanations/work in the spaces provided. However,
you may attach additional work if you want to. Write your quiz up with your name, date,
and the time and days that you attend the class. Show all work for full credit. Your
submitted quiz should be neat, clear and detailed. It should not be a rough draft. When
in doubt, include as much relevant, correct information pertaining to your answer as
possible. Remember, start early and seek out help if you “get stuck.” There are two
printed pages to this quiz.
1. (2 pts.) What proportion of sample proportions have a value greater than the
population proportion in any normal sample proportion distribution?
2. A magazine reported that 6% of American drivers read the newspaper while
driving. Suppose that 300 drivers are selected at random and that 25 of them say
that they read the newspaper while driving.
a) (3 pts.) What are the mean and standard deviation of the sampling distribution
of sample proportions for random samples of 300 American drivers? Show
how you obtained these numerical values, i.e., show all work for full credit!
b) (4 pts.) Clearly, with detail, and using appropriate labeling notation, sketch
the distribution of the proportions of American drivers who read the
newspaper while driving, each obtained from random samples of 300
American drivers.
