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Quiz #2 STA2023
Basic Normal Curves
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. (3 pts.) Calculate P(z < 1.25). Round your answers to four decimal places. Don’t
put down just the answer, i.e., show all work for full credit!
2. (2 pts.) Using the Empirical Rule only, state the area under the Standard Normal
Curve between
2
−
and 2.
3. The time it takes a mechanic to rebuild the transmission of a 1992 Chevy shows the
mean is 8.4 hours and standard deviation is 1.8 hours. Assume that these times are
normally distributed.
a) (4 pts.) Clearly, with detail, and using appropriate labeling notation, sketch by
hand the distribution of hours that a mechanic spends rebuilding the transmission
of a 1992 Chevy.
