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7. Consider the data set: 104, 104, 105, 106, 106, 108, 108, 108, 110, 111, 112, 112, 114, 116, 120, 122, 125. Find the percentile rank of the data point 114. A. 62 B. 70 C. 75 D. 85 8. What is the area under the standard normal curve between z = -1.0 and z = -2.0? A. 0.0228 B. 0.1359 C. 0.3413 D. 0.4772 9. The variance and mean for a given set of data is 25 and 64, respectively. What is the standard deviation? A. 2.56 B. 5 C. 8 D. 625 10. In the standard normal curve, what z value would correspond to an area of 0.0853 to its right? A. 1.14 B. 1.34 C. 1.37 D. 1.78 11. The weight of persons in a certain study follows a normal distribution with a mean of 400 pounds and a standard deviation of 10 pounds. What is the probability of randomly selecting a person whose weight is between 400 and 415 pounds? A. 0.1932 B. 0.3413 C. 0.4332 D. 0.5000 12. A new extended-life lightbulb has an average service life of 750 hours, with a standard deviation of 50 hours. If the service life of these light bulbs approximates a normal distribution, about what percent of the distribution will be between 600 and 900 hours? A. 34% B. 68% C. 95% D. 99.7%