Researchers claim that men and women have different speech patterns, particularly ...

Researchers claim that men and women have different speech patterns, particularly in the number of words spoken per day. One widely used estimate is that a woman uses about 20,000 words per day, whereas a man uses 7,000. To investigate such claims, one study used a special device to record the conversations of male and female university students. From these recordings the daily word count of the 17

men in the study was determined. The researchers wanted to understand more about the number of words spoken by men: is there evidence that the mean number of words per day of men at this university differs from 7,000? The data are in the table and in the excel file, tab WORDS.

a) What are the experimental units in the study? What is the response variable? Quantitative or categorical?

b) Verify the two conditions for inference.

a) Random sample?

· Is n ≥30 or is x approximately normally distributed.

[Note that we do not know if the data for each man are normally distributed and the sample size n <30. So use StatKey to make a histogram of the data and verify the data are approximately normally distributed. We could also verify that the data distribution is symmetric with a boxplot. Include either the histogram or the boxplot with your submitted work.]

c) Calculate using Excel or StatKey (NOT by hand)

· x̅, the number of words spoken by a man per day

· s, the standard deviation of the words

d) Conduct a 4-step significance test to determine if the mean number of words per day of men at this university differs from 7,000. Be sure to state the conclusion in plain English, not statistics jargon.

Words spoken   by men per day

10084

15931

10575

12880

11071

17799

13182

8918

6495

8153

7015

4429

10054

3998

12639

10974

5255