verage number of miles a person drives per day is 24. A researcher wishes to see if people over age 60 drive less tha 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 α=0.01, is there sufficient evidence that those drivers over 6-60 years old drive less than 24 miles per day on average? Assume that the variable is normally distributed. Use the

Fran is training for her first marathon, and she wants to know if there is a significant difference between the mean number of miles run each week by group runners and individual runners who are training for marathons. She interviews 42 randomly selected people who train in groups and finds that they run a mean of 47.1 miles per week. Assume that the population standard deviation for group runners is known to be 4.4 miles per week. She also interviews a random sample of 47 people who train on their own and finds that they run a mean of 48.5 miles per week. Assume that the population standard deviation for people who run by themselves is 1.8 miles per week. Test the claim at the 0.01 level of significance. Let group runners training for marathons be Population 1 and let individual runners training for marathons be Population 2.   Step 2 of 3 :   Compute the value of the test statistic. Round your answer to two decimal places.

A non-symmetric dataset has a mean of 200 and a standard deviation of 15.  Find an upper bound for the proportion of data points that are either greater than 230 or less than 170.

In Professor Krugman's economics course, the correlation between the students' total scores prior to the final examination and their final‑examination scores is ?=0.5.�=0.5. The pre‑exam totals for all students in the course have mean 280280 and standard deviation 40.40. The final‑exam scores have mean 7575 and standard deviation 8.8. Professor Krugman has lost Julie's final exam but knows that her total before the exam was 300.300. He decides to predict her final‑exam score from her pre‑exam total.   © Macmillan Learning (a) What is the slope of the least-squares regression line of final-exam scores on pre-exam total scores in this course? Give your answer to one decimal place. slope:     What is the intercept? Give your answer as a whole number. intercept:

It takes an average of 14.5 minutes for blood to begin clotting after an injury. An EMT wants to see if the average will increase if the patient is immediately told the truth about the injury. The EMT randomly selected 70 injured patients to immediately tell the truth about the injury and noticed that they averaged 16.3 minutes for their blood to begin clotting after their injury. Their standard deviation was 4.75 minutes. What can be concluded at the the α = 0.10 level of significance? a. For this study, we should use [Select an answer b. The null and alternative hypotheses would be: Ho: ? Select an answer H₁: ? Select an answer ✓ c. The test statistic ? = (please show your answer to 3 decimal places.) d. The p-value = (Please show your answer to 4 decimal places.) e. The p-value is ? ✓ a f. Based on this, we should [Select an answer the null hypothesis. g. Thus, the final conclusion is that ... O The data suggest the populaton mean is significantly greater than 14.5 at a = 0.10, so…

The ages of a group of 138 randomly selected adult females have a standard deviation of 17.5 years. Assume that the ages of female statistics students have less variation than ages of females in the general population, so leto= 17.5 years for the sample size calculation. How many female statistics student ages must be obtained in order to estimate the mean age of all female statistics students? Assume that we want 95% confidence that the sample mean is within one-half year of the population mean. Does it seem reasonable to assume that the ages of female statistics students have less variation than ages of females in the general population? The required sample size is (Round up to the nearest whole number as needed.)

According to an article in Good Housekeeping, a 128-lb woman who walks for 30 minutes four times a week at a steady, four-mi/hr pace can lose up to 10 lbs over a span of a year.  Suppose 35 women with weights between 125 and 130lb perform the four walks per week for a year and at the end of the year the average weight loss for the 35 was 9.1 lbs.  If the sample standard deviation is 5, calculate the value of the test statistic and find the p-value of the hypothesis test of Ho:µ =10 vs H1:µ≠10.

In a random sample of 6 cell phones, the mean full retail price was 517.30 and standard deviation is 184.00. Further research suggests that the population mean is 425.73. Does the t-value for the original sample fall between -t0.99 and t0.99?

According to a report published by the USDA 3 years ago, a typical American consumes an average of 26 pounds of ice cream per year. A researcher at the USDA would like to determine if the average amount of ice cream consumed each year by a typical American has changed since the original report was published. The researcher collected data from a random sample of 65 Americans and found that the mean amount of ice cream consumed each year by the sample was 25.54 pounds with a standard deviation of 1.64 pounds. Using α=0.02, test the hypothesis that the mean amount of ice cream consumed each year by a typical American is different than 26 pounds. Use the p-value method. State the null and alternative hypothesis for this test.  H0= H1= Determine the test statistic for the hypothesis test. Round the solution to four decimal places. =