a. Calculate a 95% confidence interval for the mean number of hours slept in the Population, using the one-sample t confidence interval procedure. b. Doctors recommend 8.0 hours of sleep per night. Does the population sleep fewer hours per night, on average, than this recommendation? Answer this question using a one-sample t test with a=.05. State your conclusion c. Discuss whether the data meet the distributional and sample size requirements for the t procedures you used in part a and b

K A large family-held department store had the business objective of improving its response to complaints. The variable of interest was defined as the number of days between when the complaint was made and when it was resolved. Data were collected from 40 complaints that were made in the last year. Use the data to complete parts (a) through (d) below. Click the icon to view the data table. a. Construct a 99% confidence interval estimate for the population mean number of days between the receipt of a complaint and the resolution of the complaint. The 99% confidence interval estimate is from (Round to one decimal place as needed.) View an exar Complaint Data Days Between Complaint and Resolution of Complaint 30 12 6 23 32 153 18 38 ENMASONR2 27 3 131 15 6 74 70 29 days to days. Print 46 133 41 104 4 10 22 16 94 20 45 81 10 27 22 40 Done 2 21 22 13 25 52 14 32 - < answer In

1. The data below represent the repair cost for a low-impact collision in a simple rnadom sample of mini- and -micro vehicles $3148 $1758 $1071 $3345 $743 $2057 $663 $2637 $773 $1370 1a. Determine the point estimate of the population mean. Use the appropriate notation. 1b. Determine the margin of error for the 90% confidence interval. Use appropriate notation. 1c. Specify the 90% confidence intervalUse appropriate interval notation. 1d. Give a brief intperetation of the confidence intervalas related to repair costs. 2. Use the data from the problem #1. Assume a probability normal probability plot suggest the data could come from a population that is normally ditrubuted. A bocplot does not show outliers. Does the sample evidence suggest the cost of repairs to exceed $1200? 2a. what type of test should we use? ____  sample ___ - test for the _____ 2b. Write the hypothesis and specify the type of testing (failing). Use appropriate notation for the hypothesis. Hypothesis: Tailing:…

1a) Work Time Lost due to Accidents At a large company, the Director of Research found that the average work time lost by employees due to accidents was 97 hours per year. She used a random sample of 22 employees. The standard deviation of the sample was 5.8 hours. Estimate the population mean for the number of hours lost due to accidents for the company, using a 90% confidence interval. Assume the variable is normally distributed. Use a graphing calculator and round the answers to the nearest whole number. ___ < μ < ___   1b) Hospital Noise Levels For a sample of 26 operating rooms taken in a hospital study, the mean noise level was 43.9 decibels, and the standard deviation was 8.9. Find the 97% confidence interval of the true mean of the noise levels in the operating rooms. Assume the variable is normally distributed. Use a graphing calculator and round the answers to at least one decimal place. ___ < μ < ___   1c) Unhealthy Days in Cities The number of unhealthy days…