A survey of nonprofit organizations showed that online fundraising has increased in the past year. Based on a random sample of 50 nonprofits, the mean one-time gift donation in the past year was $29, with a standard deviation of $9. Complete parts a and b below. a. Construct a 99% confidence interval estimate for the population one-time gift donation. sμ≤ (Type integers or decimals rounded to two decimal places as needed.) b. Interpret the interval constructed in (a). Choose the correct answer below. A. The quality improvement team can be 99% confident that the new population mean turnaround time is the midpoint of the confidence interval. B. The quality improvement team can be completely sure that the new population mean turnaround time is contained within the confidence interval. C. The quality improvement team can be 99% confident that the new population mean turnaround time is contained within the confidence interval. D. The quality improvement team can be completely sure that the new population mean turnaround time is the midpoint of the confidence interval.

supervisor records the repair cost for 17 randomly selected TVs. A sample mean of $76.76and standard deviation of $24.02 are subsequently computed. Determine the 99% confidence interval for the mean repair cost for the TVs. Assume the population is approximately normal. Step 1 of 2:  Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places.

In a random sample of 60 refrigerators, the mean repair cost was $111.00 and the population standard deviation is $16.40. Construct a 95% confidence interval for the population mean repair cost. Interpret the results. Construct a 95% confidence interval for the population mean repair cost. The 95% confidence interval is ( D. (Round to two decimal places as needed.)

A consumer affairs investigator records the repair cost for 4 randomly selected TVs. A sample mean of $75.89 and standard deviation of $13.53 are subsequently computed. Determine the 80% confidence interval for the mean repair cost for the TVs. Assume the population is approximately normal.  Construct the 80% confidence interval. Round your answer to two decimal places.

A survey of 73 randomly selected homeowners finds that they spend a mean of $74 per month on home maintenance. Construct a 95% confidence interval for the mean amount of money spent per month on home maintenance by all homeowners. Assume that the population standard deviation is $16 per month. Round to the nearest cent.

You measure 37 textbooks' weights, and find they have a mean weight of 69 ounces. Assume the population standard deviation is 12.9 ounces. Based on this, construct a 80% confidence interval for the true population mean textbook weight.Report your answers to three decimal places.

In a random sample of 38 criminals convicted of a certain​ crime, it was determined that the mean length of sentencing was 61 ​months, with a standard deviation of 8 months. Construct and interpret a 95​% confidence interval for the mean length of sentencing for this crime. Select the correct choice below and fill in the answer boxes to complete your choice.​(Use ascending order. Round to one decimal place as​ needed.) A. 95​% of the sentences for the crime are between ____ and ____ months.  B. There is a 95​% probability that the mean length of sentencing for the crime is between ____ and ____ months.   C. We can be ​95% confident that the mean length of sentencing for the crime is between

A statistician selected sample of 16 accounts reviewable and determined the mean of the sample to be $5,000 with a standard deviation of $400. She reported that the sample information indicated the mean of the population ranges from $4,739.80 to $5,260.20. She did not report what confidence coefficient she has used. Based on the above information, determine the confidence coefficient that was used.