Question 1187603: The results of the latest writing of the LSAT (Law School Aptitude Test) showed results that were normally distributed with a mean score of 867 and a standard deviation of 50.
(a) What percent of students scored between 777 and 987?
(b) What percent of students got 1004 or more on the test?
(c) The Osgoode Hall Law School wants candidates for admission to be in the top 14
% of LSAT test scores. What is the minimum test score a candidate needs to achieve to be considered for admission to this school?
(d) If a group of 46 applicants is randomly selected, what is the probability that the group average is not less than 887?
Answer by Boreal(15235)   (Show Source):
You can put this solution on YOUR website! a. z=(x-mean)/sd or (777-867)/50 or -1.8
and (987-867)/50 or 2.4
That probability that z is between those two is 0.9559
b. z > 137/50 or 2.74, with probability 0.0031
c. want z for 86th percentile and that is invnorm(0.86,0,1), or 1.08
1.08=(x-867)/50
x=921.
d. this is z>(887-867)/(50/sqrt(46) or 20*sqrt(46)/50 or 2.713, and that probability is 0.0033
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