SOLUTION: It is estimated that 60% of the candidates who took an aptitude test passed. If 800 of such candidates are selected and the selection follows a normal approximation, find the proba
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Question 1180060: It is estimated that 60% of the candidates who took an aptitude test passed. If 800 of such candidates are selected and the selection follows a normal approximation, find the probability that;
I. Between 450 and 500
II. Not less than 510
III. Not more than 515 of the candidate passed the test. Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website! Mean is np=800*0.6=480
variance is np(1-p)=480*0.4=192
sd is sqrt(V)=13.86
between 450 and 500 is using 449.5 and 500.5 with the continuity correction factor.
this is between z=(449.5-480)/13.86=-2.201 and z=(500.5-480)/13.86=1.479
that probability is 0.9166
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not less than 510 is z >(510-480)/13.86=2.165, and that probability is 0.0152
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not more than 515 is z <(515-480)/13.86=2.525, and that probability is 0.9942
