a. http://en.wikipedia.org/wiki/Standard_deviation
b. 95% = mean ± 1.96 SD
c. Z = (score-mean)/SD
d. Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion from the Z score, using equation above.
e. Use same equation.
f. Use same table to find Z score and calculate.
Reading placement scores for a particular college are normally distributed with a mean of 72 and a standard deviation of 7.
a) draw a sketch of the reading placement scores for students at this college. be sure to mark the mean and also to mark one and two standard deviations from each side of the mean.
b) 95% of students at this college have a reading placement score between ______ and ______
c) Sammy's reading placement score is 82. What is his z-score?
d) Find the proportion of students at this college who have a reading placement score of at least 82.
e) Elisa's z-score is -1.5. What is her reading placement score?
f) How high does one's reading placement score have to be so that a student is in the 85th percentile?
1 answer
1 answer