## describe how to apply stratified sampling to sample from the credit risk data file based on the different type of loans .

1.A sample of 33 airline passengers found that the average check in time is 2.167. Based on long-term data, the population standard deviation is known to be 0.48. Find a 95% confidence interval for the mean check-in time. Please use Excel to show how you got your answer.

2. your college or university wishes to obtain reliable information about student perception of administrative communication . describe how to design a sampling plan for this situation based on your knowledge of the structure and organization of your college or university. how would you implement simple random sampling, stratified sampling and cluster sampling for this study? what would be the pros and cons of using each of these methods?(answer this qustion in excel but very short answer)

3. using sata in excel file college and university find 95% confidence intervals for the median SAT for each of the tow groups , liberal arts colleges and research universities. based on these confidence intervals , does there appear to be a difference in the median SAT scores between the groups? the excel attatced

4.if based on a sample size of 850, a political candidate finde that 458 people would vote for him in a two person race, what is the 95% confidence interval for his expected proportion of the vote? would he be confident of winning based on this poll? use the appropriate formula and verify your result using the confidence intervals workbook

5.describe how to apply stratified sampling to sample from the credit risk data file based on the different type of loans . implement your process in excel to choose a random sample consisting of 10% of the records for each type of loan.p