NO PLAGERIASM, MUST BE ORIGINAL WORK!!!
USE DATA SHEET GIVEN TO MAKE ANY CALCULATIONS SHOWING ALL WORK WITH FORMULAS IN CELLS, ANSWERS ALONE WILL NOT SUFICE.
WORD DOCUMENT MUST HAVE AT LEAST 700 WORDS WITH REFERENCES LISTED IN APA FORMAT. MUST ANSWER EVERY BULLET POINT PROPERLY.
Resources: Microsoft Excel®, The Payment Time Case Study, The Payment Time Case Data Set
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 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.