Reference no: EM131332543
Starting in 1998, a series of credit card usage studies have been performed by Sallie Mae, a major provider of educational loans and savings programs. In a recent pilot study, a random pool of 122 loan applicants attending four-year colleges had their credit card data pulled for analysis. The sample mean credit card balance was $3173. The standard deviation was $3216.
(a) Compute a 95% confidence interval for the mean credit card balance among all undergraduate loan applicants (studying at four-year colleges).
(b) Provide the ‘correct' interpretation of your interval.
(c) Sally Mae would like to repeat this survey but with a sample size large enough to achieve a margin of error of $100. How many credit card records should they analyze in order to achieve this margin of error with 95% confidence? You should use the results of the pilot survey in part (a) in answering this question.
(d) Researchers at Sally Mae were interested not only in the actual balances in the pilot survey described above. They were also interested in using the 122 records to estimate the percentage of all credit card balances that exceeded $10,000. In fact, 23 of the 122 balances in the pilot survey exceeded $10,000. Use this result to find an 80% confidence interval for the percentage of all credit card balances that exceeded $10,000.
(e) To the extent possible, check the validity of the conditions associated with your confidence interval in part (d).
(f) Explain carefully how you would use your confidence interval in part (d) to perform a two-sided test of whether a quarter of all balances exceed $10,000. What decision is appropriate? What level of significance is implied in this test?
What is the test value for hypothesis test
: He surveys a sample of 40 students and finds that for the most recent semester their average cost was $430 with a standard deviation of $80. What is the test value for this hypothesis test?
|
Depict the situation as a game with incomplete information
: Depict the situation as a game with incomplete information, in which each type of each player is indexed by the number of e-mail messages he has received.
|
Analyze each metric to determine its application
: Identify five metrics that you would include in measuring the success of an organization's talent management function.Analyze each metric to determine its application and relevance for success.Would you assign an equal weight to the metrics you chos..
|
Is risk management part of engineering asset management
: ENGG958 Life Cycle and Risk Management Assignment 4: A workplace-based report. What are the risks or risk categories that engineering asset management have to deal with? Is risk management part of engineering asset management? What key issues of risk..
|
Series of credit card usage studies
: Starting in 1998, a series of credit card usage studies have been performed by Sallie Mae, a major provider of educational loans and savings programs. In a recent pilot study, a random pool of 122 loan applicants attending four-year colleges had t..
|
Describing key design decisions and features of your code
: Create a web page that will allow users to choose between alternative times for sessions that run more than once, i.e. have multiple occurrences - you must complete the design commentary task by describing key design decisions and features of your ..
|
Sample summary statistics in the output
: Use the sample summary statistics in the output to verify the value for t in this case. What is the p-value corresponding to your alternative hypothesis?
|
Mean and standard deviation of the times
: (a) State the null and the alternative hypothesis in this case. Define (in words) the parameter of interest in this case. A total of 12 mice attempted the maze while loud rap music was being played. The mean and standard deviation of the times to c..
|
Application of the ideas in statistical inference
: 1. Here are several situations in which there is an incorrect application of the ideas in statistical inference. Write a sentence or two in each case explaining what is wrong and why it is wrong. (a) A significance test rejected the null hypothesi..
|