Use a t-distribution to find a confidence interval for the difference in means 4 = µ - H2 using the relevant sample results from paired data. Assume the results come from random samples from populations that are approximately normally distributed, and that differences are computed using d = x1 - X2. A 99% confidence interval foru, using the paired data in the following table: Case 1 2 4 Treatment 21 27 30 26 29 1 Treatment 17 29 24 21 22 Give the best estimate foru, the margin of error, and the confidence interval. 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 = to i The 99% confidence interval is

Age Differences In a large hospital, a nursing director selected a random sample of 43 registered nurses and found that the mean of their ages was 31.5. The population standard deviation for the ages is 4.5. She selected a random sample of 32 nursing assistants and found the mean of their ages was 29.7. The population standard deviation of the ages for the assistants is 5.3. Find the 95% confidence interval of the differences in the ages. Use μ1 for the mean age of the nursing assistants. Round the answers to at least one decimal place. Use a TI-83 Plus/TI-84 Plus calculator. ? < μ1- μ2 < ?

Find the critical value x²R corresponding to a sample size of 19 and a confidence level of 99 percent. X²R = (Round to 3 decimals)

In a random sample of 19 people, the mean commute time to work was 33.6 minutes and the standard deviation was 703 minutes. Assume the population is normally distributed and use a t- distribution construct a 80% confidence interval for the population mean u. What is the margin error of u? Interpret the results.

One method for measuring air pollution is to measure the concentration of carbon monoxide, or CO, in the air. Suppose Nina, an environmental scientist, wishes to estimate the CO concentration in Zagreb, Croatia. She randomly selects 45 locations throughout the city measures the CO concentration at each location. Based on her 45 samples, she computes the margin of error for a 95% t-confidence interval for the mean concentration of CO in Zagreb, in µg/m³, to be 4.28. What would happen to the margin of error if Nina decreases the confidence level to 90%? Nina increases the confidence level to 99%? Nina decreases the sample size to 33 locations? Nina increases the sample size to 65 locations? Answer Bank Increase Stay the same Decrease