Ethics in Research (Percentage Between)
Problem 1 The mean 75 with a standard deviation of 23. Determine percentages that fall between these pairs of scores:
52 and 98, 29 and 121, 56 and 71, 100 and 122, 35 and 125
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Problem 1 Answers
Raw 52.00 Raw 98.00
Z -1.00 Z 1.00
Percent between = 68.26%
Raw 29.00 Raw 121.00
Z -2.00 Z 2.00
Percent between = 95.44%
Raw 56.00 Raw 71.00
Z -0.83 Z -0.17
Percent between = 22.92%
Raw 100.00 Raw 122.00
Z 1.09 Z 2.04
Percent between = 11.72%
Raw 35.00 Raw 125.00
Z -1.74 Z 2.17
Percent between = 94.41%
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Problem 2 The mean of 42 and a standard deviation of 18.
a. What is the percentage of scores that fall between 77.28 and 6.72
b. What is the percentage between 43 and 50
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Problem 2 Answers
a. The percentage of scores that fall between 77.28 and 6.72 is 95%
b. The percentage between 43 and 50 is 14.61%
(or .15.01% when Z-Score of .055 is not rounded to .06)
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Problem 3 Mean is 200, standard deviation is 35. What is percentage between 145 and 180
Problem 3 Answer The percentage between 145 and 180 is 22.61%
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Problem 4 The mean is 8,000, standard deviation of 2500:
a. What is the percentage between 5750 and 9750
b. What is the percentage between 8000 and 10500
Problem 4 Answer a. About 58% b. 34.13%
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Problem 5 The mean is 200 with a standard deviation of 25. What is the percentage between 183 and 240?
Problem 5 Answer The percentage between 183 and 240 is 69.70%
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Problem 6 a. What is the percentage between 491 and 518 when = 500 and s = 100?
b. What percentage of scores fall between 72 and the mean when = 50 and s = 10?
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Problem 6 Answer a. 10.73% b. 48.61%