# Res 342 Final Exam Answer Key

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1) The statement that determines if the null hypothesis is rejected or not is called the A. critical value B. alternate hypothesis C. test statistic D. decision rule 2) The normally distributed AAA battery life is stated to be 350 days when used in a clock radio. The Big Charge Battery Company has recently modified the AAA batteries so as to extent their life. The owner of the company wanted to know if the improved batteries really did last significantly longer. A sample of 100 of the improved batteries was tested. It was discovered that the mean life was 362 days and the sample standard deviation was 10 days. The research department decided to conduct the test at the 0.05 level of significance whether the modification actually increased the life of the AAA battery. What was their decision rule? A. Reject the null hypothesis if computed z is 1.96 or greater. B. Do not reject the null hypothesis if computed z is 1.65 or greater. C. Reject the null hypothesis if computed z is less than 1.96. D. Do not reject the null hypothesis if the z test statistics is 1.96 or greater. 3) The area of rejection, on a bell shaped curve, defines the location of all those values that are A. so small or so large that the probability of their occurrence under a true null hypothesis is rather slim B. so small or so large that the probability of their occurrence under a true null hypothesis is to be expected C. so small or so large that the probability of their occurrence under a false null hypothesis is rather remote D. within the selected confidence interval for the test 4) The Roman Senate has become concerned about the loyalty of the army in Gaul commanded by Julius Caesar. They claim that, of the 80,000 men in the army, at least 28,000 are foreign