Use the t-distribution to find a confidence interval for a difference in means u – H2 given the relevant sample results. Give the best estimate for u – H2, the margin of error, and the confidence interval. Assume the results come from random samples from populations that are approximately normally distributed. A 95% confidence interval for 4 - 42 using the sample results = 5.7, s1 = 2.3, n1 = 11 and I2 = 4.5.s2 = 2.4.n2 = 8 Enter the exact answer for the best estimate and round your answers for the margin of error and the confidence interval to two decimal places. Best estimate = i Margin of error = i Confidence interval: i to i

A simple random sample of 60 items resulted in a sample mean of 71. The population standard deviation is 13. a. Compute the 95% confidence interval for the population mean (to 1 decimal).   Assume that the same sample mean was obtained from a sample of 120 items. Provide a 95% confidence interval for the population mean (to 2 decimals).

Suppose the retirement age in the U.S. is normally distributed with an unknown population mean and standard deviation. A random sample of 22 retirees is taken and results in a sample mean of 59 years old and sample standard deviation of 5 years.The  margin of error for a 95% confidence interval estimate for the population mean using the Student's t-distribution is 2.22. Find a 95% confidence interval estimate for the population mean using the Student's t-distribution. Round the final answers to two decimal places

Find the 95% confidence interval for the variance and standard deviation for the time it takes a state police inspector to check a truck for safety if a sample of 21 trucks has a standard deviation of 5.2 minutes. Assume the variable is normally distributed.