14. Solar cells are attached to a panel with a new heat resistant adhesive. The adhesive …
13. Answer this question using the internet or other sources. You must quote the references you cited. Explain clearly the following terms in a paragraph.
(a) Random
(b) Independent
(c) Degree of Freedom
14. Solar cells are attached to a panel with a new heat resistant adhesive. The adhesive must provide 2.80 pounds of force in order to hold the cell on the panel. A random sample of 50 cells is tested and the following forces are necessary to break the adhesive.
2.65 2.76 2.82 2.89 2.95
2.67 2.77 2.83 2.90 2.95
2.68 2.77 2.84 2.90 2.97
2.68 2.77 2.84 2.91 2.98
2.70 2.78 2.84 2.92 2.98
2.70 2.78 2.85 2.92 2.99
2.73 2.79 2.88 2.93 3.00
2.74 2.80 2.88 2.93 3.01
2.75 2.81 2.88 2.93 3.02
2.75 2.82 2.89 2.94 3.03
(a) Test at the 0.01 level of significance the hypothesis that the mean adhesive strength is at least 2.80 pounds.
(b) Assuming the data follow a normal distribution, what proportion of the cells would you estimate to be out of tolerance(i.e., less than 2.80 pounds of adhesive strength)?
(c) Discuss your results from part a and b above. Is a test for the mean appropriate in this case? Why or why not?
15. A medical researcher is testing a new drug to see if it slows the growth of malignant tumors in rats. The control group of 40 rats is given none of the drug and the test group of 40 rats is given a dose every day for two weeks. At the end of the test, the following statistics were calculated.
Control Rats Test Rats
Average growth of tumor 6.2 grams 4.1 grams
Standard Deviation 3.1 grams 2.8 grams
Conduct the appropriate hypothesis test to determine if the new drug appears to slow the mean rate of tumor growth.
