Math 210 – Minitab Assignment #3
(Due in class the day of Exam 3)
Directions:
You may work on this in groups of at most 2. If you worked with someone, place both
names in the upper right hand corner.
Turn in this page, any relevant graphs such as histograms and boxplots as well as output
supplied such as sample means, sample standard deviation, etc. This is done by
selecting the window such as a histogram or session window and then selecting Ctrl-P.
You can also right click on a graph or highlight the output in the session window, then
copy the information into Word.
Label all output by hand so that it is easy to find (i.e. Histogram for 1a, Means for 2c,
etc.)
Answer questions on a separate piece of paper. Do not place answers on the Minitab
output.
This assignment is worth 50 points. Failure to follow the directions above will result in
the loss of points. You will not be allowed to turn this assignment in late for any
reason.
1. This is a simulation to understand the meaning of the level of confidence (80%, 90%, 95%, etc.)
for confidence intervals.
Step 1: Generate random data that is normally distributed with mean 58 and population
standard deviation 3. Create 15 rows and 50 columns.
Step 2: Obtain a 90% confidence interval for the population mean for all 50 columns. You can
do this all at once by selecting all variables. Be sure to enter 3 as the population
standard deviation. You will end up with 50 confidence intervals. Be sure to include
these when you turn this assignment in.
Step 3: Circle the confidence intervals that contain the true population mean: 58. Determine
the exact percentage that do contain 58.
If you obtained another set of 50 confidence intervals just as you did here, what percentage
would you expect to contain the true mean?
