Posted by Anonymous on .
7) A final exam in Statistics has a mean of 73 with a standard deviation of 7.73. Assume that a random sample of 24 students is selected and the mean test score of the sample is computed. What percentage of sample means are less than 70?
Z = (score-mean)/SEm
SEm = SD/√n
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability related to the Z score.
(7.73/SQRT (24) = 1.577879643, next we subtract the data value (70) from the mean (73) as follows (70 – 73 = -3); the values of the two equations are divided as follows (-3/1.577879643 = 1.901285699).