Question

1) For each problem, state the null and alternative hypotheses, calculate the critical value(s) of the statistic by which you would reject the null hypothesis and state whether or not you would reject the null hypothesis for a level α specified by each problem. If the hypothesis test requires an unpaired t-test, then you may assume that the population variances are equal. Then calculate the appropriate statistic value by hand and use the appropriate probability table to obtain the exact P-value (Z table) or to obtain an estimated P-value (T table).

You want to determine whether a chance in your process affects the absorbency of surgical drapes you are manufacturing for α = 0.05. You sample n1 = 25 drapes from your original process and obtain an average absorbency ?1 = 18.5 and a standard deviation S1 = 3.8. You then sample n2 = 15 drapes from your modified process and obtain an average absorbency ?2 = 21.0 and a standard deviation S2 = 3.5.

Answer 1