Download Stat 200 Lab 11

Stat 200 Lab 11
The symbol µ is used to represent a population mean. Hypotheses about µ are tested
using a “t-test” procedure. In Minitab, use Stat>Basic Statistics>1 Sample t
Activity 1
What is normal body temperature? In the paper cited below, the authors present evidence
that the mean normal body temperature may be less than 98.6°, the long held standard.
Mackowiak, P. A., et al. (1992), "A Critical Appraisal of 98.6 Degrees F, the
Upper Limit of the Normal Body Temperature, and Other Legacies of Carl
Reinhold August Wunderlich," JAMA, 268, 1578-1580.
I used the statistics presented in the paper to simulate body temperatures for a sample of
18 subjects.
98.2 97.8 99.0 98.6 98.2 97.8
98.4 99.7 98.2 97.4 97.6 98.4
98.0 99.2 98.6 97.1 97.2 98.5
Ø Draw a dotplot of the data. (Graph>Dotplot,). Are there outliers, or any other
unusual features of the data?
Ø Write null and alternative hypotheses about µ, the mean normal body temperature in
the population.
Ø Do a t-test of your null and alternative hypotheses.
Ø What is the sample mean?
Ø What is the p-value of the test?
Ø Based on this conclusion, what is the appropriate conclusion about your
hypotheses?
Ø Write a sentence that explains what the p-value measures in this problem.
Use Minitab to determine a 95% confidence interval for about µ, the mean normal body
temperature in the population. (Go back to Stat>Basic Statistics>1 Sample t). Write a
sentence that interprets this interval.
Activity 2
Two different medical facilities test a new medication for allergies. The concern is the
proportion of patients who experience drowsiness. With the standard medications, this
proportion is about 0.25. This proportion may be less with the new medication.
The results from the two facilities are
Facility 1: n= 60 patients, 11 patients experience drowsiness, 49 do not.
Facility 2: n = 120 patients, 21 patients experience drowsiness, 99 do not.
Write null and alternative hypotheses for p, the proportion that experience drowsiness.
Use the data from each facility separately, to test these hypotheses. Do two tests, one
based on each facility.
Stat>Basic Stats> 1 Proportion
State conclusions. Is there a difference between the two labs? If so, what do you think
causes this difference?