1: A company manufactures bars of soap that are supposed to weigh exactly (on average) 10 ounces. A sample is taken: n=20; X= 10.20 oz; s = 0.80 oz (a) Test at = .05 (b) Construct a 95% CIE of PROBLEM 2: The Momoland Springs Company claims that at most there are 1 ppm (parts per million) of benzene in their water. Test at =.05 Data: n=25; X= 1.16 ppm; s = .20 ppm PROBLEM 3: A company claims that cancer patients using drug X will live at least 10 more years. n=16; X= 8.8 year; s = 3.4 year Test at =.05 PROBLEM 4: A yogurt company claims that its yogurt ice cream has no more than 2.0 mgs. of fat. You sample 25 cups of yogurt and find that the sample mean is 2.10 milligrams and the sample standard deviation is 0.40 milligrams (a) Test the claim at the .05 significance level (b) No claim was made by the company. They took a sample with the above results and want to construct a two-sided 95% confidence interval for the population mean. The upper limit of the confidence interval is: PROBLEM 5: A school claims that the average English regents score of its students is at least 80. You sample 16 students and find that the sample mean is 76 and the sample standard deviation is 12 (a) Test the claim at the .05 significance level (b) No claim was made by the school. They took a sample with the above results and want to construct a two-sided 95% confidence interval for the population mean. The upper limit of the confidence interval is: PROBLEM 6: An LSAT preparation school claims that its review course will add at least 50 points to the score of a student retaking the LSAT exam. You sample 25 students and find that average improvement was 40 points with a standard deviation of 15 points (a) Test the claim at the .05 significance level (b) No claim was made by the school. They took a sample with the above results and ask you to construct a two-sided 95% confidence interval for the population mean. PROBLEM 7: A drug company that manufactures a diet drug claims that those using the drug for 30 days will lose at least 15 pounds. You sample 30 people who have used the drug and find that the average weight loss was 12 pounds with a standard deviation of 5 pounds. (a) Test the claim at the .05 significance level. (b) No claim was made by the company. They took a sample with the above results and ask you to construct a two-sided 95% confidence interval for the population mean. PROBLEM 8: A company wishes to determine if the average salary of its clerks is really $340. The company researcher takes a sample of 64 clerks and finds that X=$300 and s = $80. a) Test at = 0.05. b) Construct a 95% CIE of PROBLEM 9: A company claims that its toasters have an average life of at least 10 years. Use the following sample to test at = .02. n=100 X= 9.4 years s = 1.2 years PROBLEM 10: A manufacturer produces drill bits with an intended life of at least 580 hours and a standard deviation of 30 hours. A quality control scientist draws a sample of 100 bits and finds X=577. Test at =.05 to see if the machinery needs adjusting PROBLEM 11: A company claims that people using its sleeping pill will sleep for at least 8 hours a night. Use the following sample to test at = .05. n=144 X= 7.5 hours s = 1.8 hours