18. A population has a mean of # = 35 and a standard deviation o = 5. After 3 points are added to every score in the population, what are the new values for the mean and standard deviation? a) u = 38 and o = 5 b) u = 35 and o = 8 c) u = 35 and o = 5 d) u = 38 and o = 8 19. If the scores on an exam have a mean of 26 and a standard deviation of 4, what is the z-score for a score of 18? a ) 2 b) 11 c ) - 2 d) -1.41 20. What is the correct decision in a hypothesis if the data produce a t-statistic that is in the critical region? a) Reject Ha b) Fail to reject Ho c) Reject Ho d) Fail to reject Ha 21. Which of the following is true about a 95% confidence interval of the mean of a given sample: a) 95 out of 100 sample means will fall within the limits of the confidence interval. b) There is a 0.5 probability that the population mean falls within the limits of the confidence interval. c) There is a 95% chance that the population mean will fall within the limits of the confidence interval. d) 95 out of 100 population means will fall within the limits of the confidence interval