1
Quiz # 4 STA2023
p
ˆ
confidence intervals, hypothesis tests for proportions
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 three
printed pages to this quiz.
1. (11 pts. total) Extreme Water Experience is a company that provides
white-water rafting in canoes to thousands of first-time customers. A
survey of 50 randomly picked white-water canoers showed that 23 did
not want to repeat the experience.
a. Construct, showing all values substituted into your formula,
a 99% confidence interval for the true proportion of canoers
who did not wish to canoe the rapids a second time. The
confidence interval should be given in interval notation.
b. Interpret the confidence interval given in part a. Remember to interpret the result in full
english sentences (no notation, use story problem situation with units of measure where
applicable).
c. State in detail, citing values from the story problem situation, all of the reasons why we
are allowed to construct the confidence interval from part a.
