Suppose that a simple random sample of size 320 selected from a population, p, has 143 successes. Calculate the margin of error for a 99% confidence interval for the proportion of successes for the population, p. Determine the critical value, z, correct to three decimal places using a z-distribution table or software.

Suppose a random sample of 28 customers shows an average transaction amount of $45, with a standard deviation of $12. Find the lower bound of a 95% confidence interval for the population mean of transaction amount

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…

Because Mike and Ikes are your favorite candy, you decided to apply statistics to them. Assume your bag of Mike and Ikes is a simple random sample. Suppose you have 23 Mike and Ikes. The lengths of Mike and Ikes in your bag are normally distributed with a mean of 1.5 cm and standard deviation of 0.15 cm. Create a 99% confidence interval for the variance of Mike and Ikes lengths.