STAT 332 Assignment 3 – Fall 2020

May not be reproduced in any manner without the explicit permission of Riley A. Metzger, UW 2020 Page 1

Last (Family) Name:
First (Given) Name:
Userid (i.e. rametzge):
UW ID (i.e. 20202020):
Due: Oct 9 at NOON, ONLINE in Crowdmark

Marking: Please note that the TAs may not be marking all questions in this assignment. The exact questions that will be
marked will not be determined until after the due date.

Group Work: The work handed in must be your own.

Computer Output: Please include computer code in your assignment, as well as all relevant output (some examples
where examples would be appropriate). Please do not use any libraries that do not come with the base system –
otherwise the teaching assistants will assign you a zero.

Pagination: Please use a new page for each question part. So if a question has parts a, b and c, you should have 3
separate pages.

STAT 332 Assignment 3 – Fall 2020

May not be reproduced in any manner without the explicit permission of Riley A. Metzger, UW 2020 Page 2

Question 1. The speed at which data is transmitted along fiber optic cable is given below for several diameters of cable.
The data is given below.
Diameter Speed
0.25 0.80 0.83 0.83 0.85 0.95
0.30 0.75 0.75 0.79 0.79 0.77
0.35 0.74 0.73 0.76 0.77 0.75
0.40 0.67 0.72 0.74 0.74 0.69
0.45 0.62 0.62 0.67 0.69 0.65
0.50 0.60 0.61 0.64 0.66 0.65
Part A. Does the diameter affect the mean speed? Perform an appropriate test. Make sure you include all of the steps
on an hypothesis test.
Part B. Analyze the residuals from this experiment.
Part C. Find a 95% confidence interval for the mean effect on speed when the diameter is 0.5.
Part D. Find a 95% confidence interval for the mean speed when the diameter is 0.50.
Part E. Consider the parameter = 0.25 − 0.30.
Part Ei. Find a 95% confidence interval for the parameter .
Part Eii. Test whether the parameter differs from zero.
Part F. Find a 95% confidence interval for the difference in group averages when the diameters are 0.25 and 0.3.