SOLUTION: In a recent year, a sample of grade 8 Washington State public school students taking a mathematics assessment test had a mean score of 281 with a standard deviation of 34.4. Possib

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Question 1120401: In a recent year, a sample of grade 8 Washington State public school students taking a mathematics assessment test had a mean score of 281 with a standard deviation of 34.4. Possible test scores could range from 0 to 500. Assume that the scores are normally distributed.
What percent of students had a test score that is greater than 250?
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
z>(x-mean)/sd or (250-281)/34.4
z> -31/34.4 or -0.90
That probability is 0.8159