Chapter 6.1, Problem 35AYU

Putting It Together: Sullivan Statistics Survey I One question from the Sullivan Statistics Survey I was “How many credit cards do you currently have?” This question was asked only of those individuals who have at least one credit card. Go to www.pearsonhighered.com/sullivanstats to obtain the survey results. Answer the following questions based on the results of the survey.

1. a. Determine the mean number of credit cards based on the raw data.
2. b. Determine the standard deviation number of credit cards based on the raw data.
3. c. Determine a probability distribution for the random variable, X, the number of credit cards issued to an individual.
4. d. Draw a graph of the discrete probability distribution for the random variable X. Describe the shape of the distribution.
5. e. Determine the mean and standard deviation number of credit cards from the probability distribution found in part (c).
6. f. Determine the probability of randomly selecting an individual whose number of credit cards is more than two standard deviations from the mean. Is this result unusual?
7. g. Determine the probability of randomly selecting two individuals who are issued exactly two credit cards. [Hint: Are the events independent?] Interpret this result.