Please select the best choice and leave a brief explanation as to why that is.

11. In testing the hypothesis Ho: =50 vs Ha: 50, the following was obtained: n=64,x =53.5 and =10. The test statistic value is A. t=2.8 B. t=-2.8 C. z=2.8 D. z=-2.8 12. The point that divides the region where the null hypothesis is rejected and the region where it is not rejected is the A. Critical region B. Critical value C. Test statistic D. Significance level 13. If an economist wants to determine whether there is sufficient evidence that the average monthly family income in a community exceeds Php40000, A. Either a one-tailed or two-tailed test could be used. B. A one-tailed test should be used. C. A two-tailed test should be used. D. A t-test should be used. 14. A consultant came up with a new system to increase productivity at your office. When you compared those who followed the system to those in a different office who did not adopt the system, the p-value for the comparison is 0.85. Is this system helpful? A. Probably B. It would depend on how the other office does it when it adopts the system. C. Not likely. D. Even knowing how the other office would do if the system were adopted, there is not enough information to answer the question. 15. Consider the hypothesis: Working at least 5 hours per day at a computer contributes to deterioration of eyesight. The alternative hypothesis is: A. Working for less than 5 hours a day at a computer contributes to deterioration of eyesight. B. Working at least 5 hours a day at a computer does not contribute to deterioration of eyesight. C. Working at least 5 hours a day at a computer contributes to the deterioration of eyesight. D. Working at least 5 hours a day at a computer improves eyesight. 16. If a hypothesis is not rejected at the 0.10 significance level, it A. Must be rejected at the 0.05 level. B. May be rejected at the 0.05 level. C. Will not be rejected at the 0.05 level. D. Must be rejected at the 0.01 level. 17. Police Supt. Kardo Dalisdis suspects there is a mole in his team. He believes that the newbie PSgt. Soriano is the mole since the leakage in the investigation occurs after Soriano transferred to Kardo's team. He thinks that the loyalty of Soriano still belongs to his former team. Which of the following situations will show that Kardo has committed a Type II error against his belief? A. He did not fire Soriano and finds out that he is not the mole in his team. B. He fires Soriano and finds out that he is the mole in his team. C. He did not fire Soriano and finds out that he is the mole in his team. D. He fires Soriano and finds out that he is not the mole in his team. 18. As the degrees of freedom for the t distribution increases, the distribution approaches A. a value of zero for the mean B. the t distribution C. the normal distribution D. the F distribution 19. Which of the following statements is not true about hypothesis tests? A. Hypothesis tests are only valid when the sample is representative of the population for the variable of interest. B. Hypotheses are statements about the population represented by the samples. C. Hypotheses are statements about the sample/s from the population/s. D. Conclusions are statements about the population/ represented by the sample/s. 20. Which of the following is not a basic assumption for a hypothesis test concerning two population means? A. The samples are obtained from normally distributed populations. B. The level of measurement of the dependent variable is nominal. C. The level of measurement of the dependent variable is at least interval. D. The level of measurement of the grouping variable is nominal.