A study is to be conducted to estimate the daily water consumption per person. If the population standard deviation is 10,000 litres, what should the sample size be so that the length of the 90% confidence interval does not exceed 500 litres? Select one: a. 1082 b. 1083 C. 4330 d. 1537 e. 1538

At a charter high school, the average GPA of a high school senior is known to be normally distributed. After a sample of 27 seniors is taken, the average GPA is found to be 2.85 and the sample variance is determined to be 0.16. Find a 95% confidence interval for the population mean GPA.   a. 2.5615 to 2.8585 b. 2.6358 to 3.0642 c. 2.6917 to 3.0083 d. 2.5167 to 2.9033

If n=22, (x-bar)=34, and s=17, construct a confidence interval at a 99% confidence level. Assume the data came from a normally distributed population. Give your answers to one decimal place.

Use the information provided to find the minimum sample size required to estimate an unknown parameter Mean(u). How many students should be randomly selected to estimate the average weekly earnings of students at a university? We want 80% confidence that the sample mean is within $ 3 of the population mean and the population standard deviation is known to be $ 57. Select one: a. 978 b. 362 c. 1388 d. 594 e. 2397

A simple random sample of 80 items from a population with o = 7 resulted in a sample mean of 35. If required, round your answers to two decimal places. a.  Provide a 90% confidence interval for the population mean.  to   b.  Provide a 95% confidence interval for the population mean.  to   c.  Provide a 99% confidence interval for the population mean