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A class has an equal number of boys and girls. The boys all got 89% on...

A class has an equal number of boys and girls. The boys all got 89% on a test and the girls all got 75%. What are the mean and standard deviation of the test scores for the entire class?

Find the Mean and Standard Deviation.

math   Statistics-And-Probability   
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Answer #1

Mean = (89 + 75)/2

= 82%

Standard deviation = [(89-82)2 x 0.5 + (75-82)2 x 0.5]0.5

= 7%

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