SOLUTION: a population of 5,000 test scores are found to be normally distributed with a mean if 50 and a standard deviation of 10. What percentage of scores are below 55

Algebra ->  Probability-and-statistics -> SOLUTION: a population of 5,000 test scores are found to be normally distributed with a mean if 50 and a standard deviation of 10. What percentage of scores are below 55      Log On

 

Hi

*Note: 

 z =(55-50)/10 = 5/10 = .5

 P( x <55) = .6915   69.15% of the scores

Percentage under the graph to the left of the green line: z=.5