The normal distribution (68–95–99.7 rule)

Question 1

Scores have mean 46 and standard deviation 11. What is the z-score of 35?

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Question 2

A variable is normally distributed with mean 76 and standard deviation 13. About what percentage of values lie between 50 and 102?

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Question 3

Scores have mean 88 and standard deviation 4. What is the z-score of 80?

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Question 4

A variable is normally distributed with mean 67 and standard deviation 2. About what percentage of values lie between 65 and 69?

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Question 5

Scores have mean 108 and standard deviation 10. What is the z-score of 98?

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Question 6

A variable is normally distributed with mean 134 and standard deviation 7. About what percentage of values lie between 113 and 155?

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Question 7

Scores have mean 95 and standard deviation 9. What is the z-score of 117.5?

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Question 8

A variable is normally distributed with mean 151 and standard deviation 11. About what percentage of values lie between 140 and 162?

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Question 9

Scores have mean 117 and standard deviation 5. What is the z-score of 127?

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Question 10

A variable is normally distributed with mean 127 and standard deviation 4. About what percentage of values lie between 123 and 131?

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Question 11

Scores have mean 67 and standard deviation 5. What is the z-score of 74.5?

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Question 12

A variable is normally distributed with mean 148 and standard deviation 11. About what percentage of values lie between 137 and 159?

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Question 13

Scores have mean 83 and standard deviation 7. What is the z-score of 72.5?

Answer 

Question 14

A variable is normally distributed with mean 83 and standard deviation 14. About what percentage of values lie between 69 and 97?

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Question 15

Scores have mean 58 and standard deviation 12. What is the z-score of 40?

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Question 16

A variable is normally distributed with mean 134 and standard deviation 13. About what percentage of values lie between 95 and 173?

Answer