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Alfred McStatti <- Change this to your name!!!!
Part I. Methodology
For my question I chose the one about watching TV because I love everything on TV, and I always have
wondered since I was a little boy whether gender has an effect on TV watching.
Question #21: How many minutes of TV do you watch each week?
I worked with Doug Statman to ensure we did everything right, but we picked different questions for our
individual reports.
Part II. Create a confidence interval
Let µ be the mean number of minutes of TV per week watched among all SU students. From the data I collected,
I have a sample mean of x-bar = 81.7 minutes, sample standard deviation of s = 63.7 minutes, and a sample size
of 250. The resulting TInterval command tells me that the 95% confidence interval for µ is (73.8, 89.6). That is,
we can be 95% confident that the average number of minutes of TV per week watched among all SU students is
between 73.8 minutes and 89.6 minutes.
Part III. Create summary table separated by gender
Summary statistics for TV watching (minutes) grouped by sex
Sex
Female
Male
n
142
108
Mean
82.12
83.09
Std. dev.
72.154
54.579
Median
60.0
67.5
Min
0
0
Max
360
300
Q1
30
60
Part IV. Create Side-by-Side Boxplots
We can visualize the five number summary from the table above thanks to the good folks who created the
website, http://www.imathas.com/stattools/boxplot.html
Q3
120
120
Part V. Find a confidence interval for the difference in means by gender
Let µ1 be the average number of minutes of TV per week watched among all male SU students, and let µ 2 be
the average number of minutes of TV per week watched among all female SU students. We can estimate the
value of µ 1 – µ 2 using a calculator:
Calculator Input (for 2-SampTInterval)
X1-bar:
Sx1:
n1:
X2-bar:
Sx2:
N2:
Pooled:
83.1
54.6
108
82.1
72.2
142
No
Result and Conclusion
I’m 95% confident that the true value of the difference µ 1 – µ 2 is between –14.76 and 16.76 minutes. Since this
interval includes both positive and negative numbers, we do not have sufficient evidence to conclude that men
and women differ in the average amount of time they watch television.