When Mrs. JHixson gave a test, the scores were normally distributed with a mean of 78 and a standard deviation of 6. This means that 95% of her students scored between which two scores?

A. 72 and 84

B. 66 and 90

C. 60 and 96

D. 60 and 100

Question

Mathematics

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12 January, 21:48

When Mrs. JHixson gave a test, the scores were normally distributed with a mean of 78 and a standard deviation of 6. This means that 95% of her students scored between which two scores?

A. 72 and 84

B. 66 and 90

C. 60 and 96

D. 60 and 100

+4

Answers (1)

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Aiden Hickman · Answer 1

For normal distribution 95% lie in the range mean-2*standard deviation for lower bound and mean+2*standard deviation for upper bound.

Upper bound is 78+2*6=78+12=90

Lower bound is 78-2*6=78-12=66

B. 66 and 90

When Mrs. JHixson gave a test, the scores were normally distributed with a mean of 78 and a standard deviation of 6. This means that 95% of her students scored between which two scores?A. 72 and 84B. 66 and 90C. 60 and 96D. 60 and 100

When Mrs. JHixson gave a test, the scores were normally distributed with a mean of 78 and a standard deviation of 6. This means that 95% of her students scored between which two scores?

A. 72 and 84

B. 66 and 90

C. 60 and 96

D. 60 and 100