Do Now Take out review so I can come check Grab a chromebook for a partner quizizz (one chromebook shared between 2 people)

Final Review 2017-2018

Problem 1 A researcher wishes to estimate the number of days it takes an automobile dealer to sell a Chevrolet Aveo. A sample of 50 cars had a mean time on the dealer’s lot of 54 days. Assume the population standard deviation to be 6.0 days. Find the 95% confidence interval of the population mean. 52.3 < 𝜇 < 55.7

Problem 2 Ten randomly selected people were asked how long they slept at night. The mean time was 7.1 hours, and the standard deviation was 0.78 hour. Find the 95% confidence interval of the mean time. Assume the variable is normally distributed. 6.54 < 𝜇 < 7.66

Problem 3 A sample of 500 nursing applications included 60 from men. Find the 90% confidence interval of the true proportion of men who applied to the nursing program. .096 < p < 0.144 or 9.6% < p < 14.4%

Problem 4 Honors Find the 95% confidence interval for the variance and standard deviation of the nicotine content of cigarettes manufactured if a sample of 20 cigarettes has a standard deviation of 1.6 milligrams. (So you should have 2 intervals) 1.2 < 𝜎 2 < 2.3

Problem 5 Find the test value for the following. Do NOT complete the entire test A researcher claims that the average cost of men’s athletic shoes is less than $80. He selects a random sample of 36 pairs of shoes from a catalog and finds the average cost of the sample is 75. Assume the standard deviation is 19.2 for the population. Is there enough evidence to support the researcher’s claim at alpha=0.10? Z = -1.56

Problem 6 Find the test value for the following. Do NOT complete the entire test A medical investigation claims that the average number of infections per week at a hospital in southwestern PA is 16.3. A random sample of 10 weeks had a mean number of 17.7 infections. The sample standard deviation is 1.8. Is there enough evidence to reject the investigator’s claim at alpha=0.05? t = 2.46

Problem 7 Find the P-value for the following. Do NOT complete the entire test A researcher claims that the average wind speed in a certain city is 8 miles per hour. A sample of 32 days has an average wind speed of 8.2 miles per hour. The standard deviation of the population is 0.6 mile per hour. At alpha=0.05, is there enough evidence to reject the claim? P-value = 0.0588

Problem 8 Find the test value for the following. Do NOT complete the entire test A dietician claims that 60% of people are trying to avoid trans fat in their diets. She randomly selected 200 people and found that 128 people stated that they were trying to avoid trans fats in their diets. At alpha = 0.05, is there enough evidence to reject the dietician’s claim? z = 1.15

Problem 9 Find the test value for the following. Do NOT complete the entire test A hospital administrator believes that the standard deviation of the number of people using outpatient surgery per day is greater than 8. A random sample of 15 days is selected. The data shown that the standard deviation of the sample is 11.2. At alpha=0.10, is there enough evidence to support the administrator’s claim? Assume the variable is normally distributed. 𝑥 2 = 27.44

Problem 10 Find the P-value for the following. Do NOT complete the entire test An attorney claims that more than 25% of all lawyers advertise. A sample of 200 lawyers in a certain city showed that 63 had used some form of advertising. At alpha = 0.05, is there enough evidence to support the attorney’s claim? P-value = 0.0170

What to Study Confidence Intervals (z, t, p, Honors- chi-squared) Hypothesis test (z, t, p, chi-squared) Critical Values- how to find critical values for ALL tests (z, t, p, chi-squared) Two sample mean hypothesis test Two sample proportion hypothesis test When to use each test!!!