The national average for mathematices on a standardized test in 2011 was 513. Su
ID: 3068550 • Letter: T
Question
The national average for mathematices on a standardized test in 2011 was 513. Suppose that the distribution of scores was approximately bell-shaped and that the standard deviation was approximately 41. Round your answers to one decimal place as needed. Part 1 within what boundaries would you expect 99.7% of the scores to fall? About 99.7% of the scores should fall between 390 and 636 - Part 2 out of 2 What percentage of scores would be above 554? % of the scores would be above 554. NEXT )? Show MoreExplanation / Answer
1)as 3 std deviation values from mean contains 99.7 % of data
therefore 99.7% of the score should fall between 513-/+ 3*41 =390 and 636
2)
z score for 554 =(X-mean)/std deviaiton=(554-513)/41=1
16 % of the scores would be above 554.
( please try 15.87 % if above 16% comes wrong)