Listed below are speeds (mi/h) measured from traffic on a busy highway. This simple random sample was obtained at 3:30 P.M. on a weekday. Use the sample data to construct a 98% confidence interval estimate of the population standard deviation. 65 64 64 57 64 55 61 60 61 69 58 66 Click the icon to view the table of Chi-Square critical values. The confidence interval estimate is mi/h

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 < ?

Use the standard normal distribution or the t-distribution to construct a 90% confidence interval for the population mean. Justify your decision. If neither distribution can be used, explain why. Interpret the results. In a random sample of 40 people, the mean body mass index (BMI) was 26.6 and the standard deviation was 6.13.

Daily Driving The average number of miles a person drives per day is 24. A researcher wishes to see if people over age 60 drive less than 24 miles per day. She selects a random sample of 25 drivers over the age of 60 and finds that the mean number of miles driven is 23.4. The population standard deviation is 4.1 miles. At a = 0.01, is there sufficient evidence that those drivers over 60 years old drive less than 24 miles per day on average? Assume that the variable is normally distributed. Use the critical value method with tables. Part 1 of 5 State the hypotheses and identify the claim with the correct hypothesis. H: u = 24 not claim Η: μ 24 claim The hypothesis test is a one-tailed test. Part: 1/5 Part 2 of 5 Find the critical value(s). Round the answer to at least two decimal places. If there is more than one critical value, separate them with commas. Critical value(s):