Z = (score-mean)/SD
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions related to your Z scores, then convert to number.
In an intelligence test administered to 1000 childrens the average score is 42 and standard deviation 24.find (i)the number children exceeding the score 60.
(ii) the number of the children with score lying between 20 and 40.
2 answers
750