IDS 270 Final Exam
UIN:______________________________
Please write your name on the top of the back of the very last page of what you turn in. You MUST show your
work for credit.
There are multiple version of the exam being used during this examination period. If your exam shows work
that is based on information from a different version of the exam then you will receive a zero for the entire
exam. Initial to acknowledge: __________
1. Define each of the following completely (including reference to the sample vs. the population where
appropriate). 5 Points
mu—
s—
sigma—
x-bar—
sampling distribution—
2. (10 pts.) A random sample of 36 postal workers is taken and their number of years on the job is recorded. The
calculated average number of years is 8 and the standard deviation calculated from the sample is 4 (s=4). Find a
90% confidence interval for the population mean number of years on the job for postal workers. Show all work.
3. (4 pts.) Could you have used the results of the previous problem to test the following
hypothesis at alpha=0.10:
Ho: mu=7.5 vs.
