The Gallup Poll interviewed 1022 randomly selected U.S. adults aged 18 and older, March 7-10, 2013. Gallup reports that when asked whether respondents thought that global warming was due primarily to human activities, $57 \%$ of respondents said it was. If you can't tell, then say so-this often happens when we read about a survey.

f) Any potential sources of bias you can detect and any problems you see in generalizing to the population of interest

The Gallup Poll interviewed 1022 randomly selected U.S. adults aged 18 and older, March 7-10, 2013. Gallup reports that when asked whether respondents thought that global warming was due primarily to human activities, $57 \%$ of respondents said it was. If you can't tell, then say so-this often happens when we read about a survey.

c) The sampling frame

As the new manager of a small convenience store, you want to understand the shopping patterns of your customers. You randomly sample 20 purchases from yesterday's records (all purchases in U.S. dollars):

a) Find the quartiles using your calculator.

As part of the marketing team at an Internet music site, you want to comprehend who your customers are. You send out a survey to 25 customers (you use an incentive of $\$ 50$ worth of downloads to guarantee a high response rate) requesting demographic information. One of the variables is the customer's age. For the 25 customers the ages are:

d) Create a stem-and-leaf plot of the data using 10s as the stems and put the youngest customers on the top of the plot.

As part of the marketing team at an Internet music site, you want to comprehend who your customers are. You send out a survey to 25 customers (you use an incentive of $\$ 50$ worth of downloads to guarantee a high response rate) requesting demographic information. One of the variables is the customer's age. For the 25 customers the ages are:

c) Create a relative frequency histogram of the data using a bar width of 5 years.

An airline company is curious about the opinions of their frequent flyer customers about their suggested new routes. Specifically, they want to know what proportion of them plan to use one of their new hubs in the next six months. They take a random sample of 10,000 from the database of all frequent flyers and send them an e-mail message with a request to fill out a survey in exchange for 1500 miles.

d) Find which sampling method is used?

As the new manager of a small convenience store, you want to understand the shopping patterns of your customers. You randomly sample 20 purchases from yesterday's records (all purchases in U.S. dollars):

a) Standardize the minimum and maximum purchase using the mean and the standard deviation.

As the new manager of a small convenience store, you want to understand the shopping patterns of your customers. You randomly sample 20 purchases from yesterday's records (all purchases in U.S. dollars):

c) Find the median purchase.

As the new manager of a small convenience store, you want to understand the shopping patterns of your customers. You randomly sample 20 purchases from yesterday's records (all purchases in U.S. dollars):

d) Find the standard deviation.

As the new manager of a small convenience store, you want to understand the shopping patterns of your customers. You randomly sample 20 purchases from yesterday's records (all purchases in U.S. dollars):

b) Find the mean purchase.

A department store is planning its next advertising campaign. Since different publications are read by different market segments, they would like to understand if they should be targeting specific age segments. The results of a marketing survey are summarized in the next table by Age and Shopping Frequency at their store.

a) Find the marginal distribution of Shopping Frequency.

The next table displays attendance data collected by the Motion Picture Association of America during the period from 2009 to 2011. Figures are the number (in millions) of frequent moviegoers in each age group.

e) What percent of all frequent moviegoers in this period were people 60 years old and older who went to the movies in 2010?

The next table displays attendance data collected by the Motion Picture Association of America during the period from 2009 to 2011. Figures are the number (in millions) of frequent moviegoers in each age group.

d) What percent of frequent moviegoers in 2010 were people 60 years old and older?

The next table displays attendance data collected by the Motion Picture Association of America during the period from 2009 to 2011. Figures are the number (in millions) of frequent moviegoers in each age group.

f) Compare the conditional distributions of the age groups across years. Write a couple of sentences summarizing what you see.