Assignment StepsResources:ÿMicrosoft Excel?, The Payment Time Case Study, The Payment Time Case Data SetÿReviewÿthe Payment Time Case Study and Data Set.Developÿa 700-word report 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 æ ? 19.5 days?Using the 99% confidence interval, can we be 99% confident that æ ? 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?Formatÿyour assignment consistent with APA format.Grading GuideContentMetPartially MetNot MetComments:Review the Payment Time Case Study and Data Set.Develop a 700-word report 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 æ ? 19.5 days?? Using the 99% confidence interval, can we be 99% confident that æ ? 19.5 days??ÿ 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?Total AvailableTotal Earned3#/3Writing GuidelinesMetPartially MetNot MetComments:The paper?including tables and graphs, headings, title page, and reference page?is consistent with APA formatting guidelines and meets course-level requirements.Intellectual property is recognized with in-text citations and a reference page.Paragraph and sentence transitions are present, logical, and maintain the flow throughout the paper.Sentences are complete, clear, and concise.Rules of grammar and usage are followed including spelling and punctuation.Total AvailableTotal Earned2#/2Assignment Total#5#/5Additional comments: