The personnel director of a large corporation wishes to study absenteeism among clerical workers at the corporation’s central office during the year. A random sample of 24 clerical workers reveals the following: Absenteeism; mean 13.7 days, standard deviation, 4.0 days; 11 clerical workers were absent more than 10 days. a. Construct a 90% confidence interval estimate f

2. A food truck serves lunch every Tuesday and Thursday on the plaza in front of Van Metre Hall on the GMU Arlington campus. The number of customers varies every day, so it wants to order supplies based on the average number of customers served per day. The truck recorded how many customers were served on 40 randomly selected days, and obtained a sample mean and sample standard deviation of 145 and 17, respectively. Construct a 90% confidence interval for the mean number of customers served per day.

A real estate company is trying to estimate the cost of rent in Houston. They randomly sample 10 apartment buildings and find that the mean monthly rent payment is $980, with a standard deviation of $250. Construct a 99% confidence interval for the true mean monthly rent payment in Houston. Find the Lower end and the Upper end.

According to the website www.collegedrinkingprevention.gov, "About 25 percent of college students report academic consequences of their drinking including missing class, falling behind, doing poorly on exams or papers, and receiving lower grades overall." A statistics student is curious about drinking habits of students at his college. He wants to estimate the mean number of alcoholic drinks consumed each week by students at his college. He plans to use a 90% confidence interval. He surveys a random sample of 63 students. The sample mean is 3.7 alcoholic drinks per week. The sample standard deviation is 3.2 drinks. Construct the 90% confidence interval to estimate the average number of alcoholic drinks consumed each week by students at this college. 1. The t value is - 2. The standard error has a value of -- 3. The margin of error has a value of 4. Construct the 90% confidence interval to estimate the average number of alcoholic drinks consumed each week by students at this college.

A study was conducted to estimate hospital costs for accident victims who wore seat belts.  twenty five randomly selected cases have a distribution that appears to be approximately bell shaped with a mean of ​$9736 and a standard deviation of ​$5483. Complete parts​ (a) and​ (b). a. Construct the​ 95% confidence interval for the mean of all such costs.

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.

A sporting equipment company manufactures 15 pond dumbbells .To ensure that the production line is functioning properly , 50 dumbbells were selected at random , and their weight were recorded .The observed sample mean weight of the 50 dumbbells was 16.87 lb and the observed sample standard deviation was 1.44 lb.       A Construct a 90% confidence interval for the mean of the distribution of the weight of the manufactured dumbbells