# qnt561 the payment time case files needed attached

Purpose of Assignment

The purpose of the assignment is to develop students’ abilities in using data sets to apply the concepts of sampling distributions and confidence intervals to make management decisions.

Assignment Steps

Resources: Microsoft ExcelÂ®, The Payment Time Case Study, The Payment Time Case Data Set (Attached)

Review the Payment Time Case Study and Data Set.

Write a 500 to 700-word paper including the following calculations and using the information to determine whether the new billing system has reduced the mean bill payment time:

• Assuming the standard deviation of the payment times for all payments is 4.2 days, construct a 95% confidence interval estimate to determine whether the new billing system was effective. State the interpretation of 95% confidence interval and state whether or not the billing system was effective.
• Using the 95% confidence interval, can we be 95% confident that Âµ â‰¤ 19.5 days?
• Using the 99% confidence interval, can we be 99% confident that Âµ â‰¤ 19.5 days?
• If the population mean payment time is 19.5 days, what is the probability of observing a sample mean payment time of 65 invoices less than or equal to 18.1077 days?