Chapter 3 Supplemental Homework

1. Use the data from the first two columns of the previous supplemental homework’s data file to answer the following
questions.

a. Compare the mean data usage between the “no notice” households and the “notice” households. What conclusion can you make from this comparison?

b. Compare the median data usage between the “no notice” households and the “notice” households. What conclusion can you make from this comparison?

c. Compare the standard deviation between the “no notice” households and the “notice” households. What conclusion can you make from this comparison?

d. Of the three summaries described above, which do you think is the most meaningful here? Explain.

e. If a software update containing 3GB of data is downloaded by every single household in the “no notice” sample, but their behavior does not change otherwise, what would be the new mean of their data usage?

f. If each household in the “notice” sample downloaded the same 3GB software update but nothing else changed, what would be the new standard deviation of their data usage?

g. Provide modified boxplots of both data sets and compare them. What conclusions can you draw from this comparison?

h. Which case would be more unusual: a household in the “no notice” group using 100GB of data, or a household in the “notice” group using 400GB of data? Explain your answer.

2. Use the last two columns of the previous data file to answer the following questions.

a. Compare the means of the two groups “Satisfied” and “Not satisfied”. What conclusions can you draw from this comparison?

b. Compare the medians of the two groups “Satisfied” and “Not satisfied”. What conclusions can you draw from this comparison?

c. Compare the standard deviations of the two groups “Satisfied” and “Not satisfied”. What conclusions can you draw from this comparison?

d. Which of the three comparisons above do you think is most meaningful here? Explain.

e. Include modified boxplots of the two groups “Satisfied” and “Not satisfied”. What conclusions can you draw from comparing the two?

3. Letecia’s cousin Jupiter has been studying the age at which parents living in Avocado Park first became parents and found that the mean was 28.7, the standard deviation was 2.6 and the median was 27.

a. If a 19-year old in Avocado Park has their first child tomorrow, what effect would that have on the mean, median and standard deviation?

b. If a 28-year old in Avocado Park has their first child tomorrow, what effect would that have on the mean, median and standard deviation?

c. If a 29-year old in Avocado Park has their first child tomorrow, what effect would that have on the mean, median and standard deviation?

d. If a 42-year old in Avocado Park has their first child tomorrow, what effect would that have on the mean, median and standard deviation?

4. In the neighborhood of Avocado Park, one quarter of all restaurants have 5 or fewer employees, and one quarter have 13 or more employees.

a. Would a restaurant with 24 employees be considered an outlier? Justify your answer.

b. Would a restaurant with 25 employees be considered an outlier? Justify your answer.

c. What can you say about the median number of employees in Avocado Park restaurants?

d. Bonus question: If there is in fact a restaurant in Avocado Park with 32 employees, what would you likely be able to conclude about the SHAPE of the distribution of the
number of employees at Avocado Park restaurants?