700-word report

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 µ ≤ 19.5 days? Using
the 99% confidence interval, can we be 99% confident that µ ≤ 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? Format your assignment consistent with
APA format