Question 1 0.5 out of 0.5 points If a distribution has a mean of 50 and a standard deviation of 25, how many standard deviations is 0 from the mean? Selected Answer: A. -2 Question 2 0.5 out of 0.5 points What type of standard score has M = 0 and SD = 1? Selected Answer: B. z score Question 3 0.5 out of 0.5 points In a distribution with a mean of 100 and a standard deviation of 15, what is the probability that a score will be 115 or higher? Selected Answer: B. 16% Question 4 0.5 out of 0.5 points A score that is 2 1/2 standard deviations below the mean would have a z-score of: Selected Answer: D. -2.5 Question 5 0.5 out of 0.5 points Standard scores are raw scores which have been adjusted for the particular mean and standard deviation of the distribution from which they are derived. Selected Answer: True Question 6 0 out of 0.5 points What is the area within .7 standard deviations of the mean? Use Appendix A ( z Distribution) to answer this question. Selected Answer: 48% Response Feedback: This is twice the area between the mean and z = +0.7 from the area under the normal curve. Choice B is correct. Choices A, C, and D represent errors in logic or calculation. Question 7 0.5 out of 0.5 points Sarah and her brother Shaun go to the same high school. Sarah is a senior and Shaun is a
junior. Sarah’s English final exam raw score was 75, and her z score was –0.83. Shaun’s English final exam raw score was 75, and his z score was +.40. Which of the following conclusions must be true? Selected Answer: The mean of the senior exam was higher than the mean of the junior exam. Question 8 0.5 out of 0.5 points If a z score of 1.65 included 45% of the area under the normal curve from the mean, what percent remains above 1.65 on the X axis? Selected Answer: B. 5% Question 9 0.5 out of 0.5 points What is the area under the normal curve between z = 0.0 and z = –2.9? Use Appendix A ( z Distribution) to answer this question. Selected Answer: 49.81% Question 10 0.5 out of 0.5 points Aretha has a score of 35 on an anxiety inventory, in which higher scores mean more anxiety. The mean for scores on this inventory is 50. Should she consult a psychologist about her level of anxiety? Selected Answer: More information is needed to answer the question Question 11 0.5 out of 0.5 points The percentages or areas under the normal curve can be interpreted as probabilities. Selected Answer: True Question 12 0 out of 0.5 points Cesar’s z score is +2.0. Rhonda’s z score is +1.0. Cesar tells Rhonda that his score shows he outscored twice as many people as she did. Is he correct? Selected Answer: No, Cesar’s score is only somewhat better than Rhonda’s. Response Feedback: Normal curve theory supports the reasoning in Choice B. The reasoning is faulty in Choices A and C because 16% outscore Rhonda, compared with 2% outscoring Cesar. The reasoning is faulty in choice D because z scores are interval level measures that lack an absolute zero point.