What percent of the graduating seniors had a test score above 85? Express your answer to the nearest percent.?

2016-06-06T20:18:04Z

A school district requires all graduating seniors to take a mathematics test. This year, the test scores were approximately normally distributed for the 1208 graduating seniors. The mean score on the test was a 74 and the standard deviation was 11.

paramvenu2016-06-06T22:35:12Z

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z = (X - Mean)/SD
z = (85 - 74)/11 = + 1
Required percent = P(X > 85)*100
= P(z > 1)*100
= [1 - P(z < 1)]*100
= [1 - 0.8413]*100
= 0.1587*100
= 15.87% or 16% on rounding