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

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
-
not less than 510 is z >(510-480)/13.86=2.165, and that probability is 0.0152
-
not more than 515 is z <(515-480)/13.86=2.525, and that probability is 0.9942

RELATED QUESTIONS
A standard certification test was given at three locations. 1,000 candidates took the... (answered by macston)

The average of marks obtained by 120 candidates was 35. If the average of marks of passed (answered by ankor@dixie-net.com)

Suppose that an admission test for a certain university is designed so that the... (answered by stanbon,ewatrrr)

In an election, 72% of the candidates are dishonest, 75% are incompetent, and 60% hate... (answered by ikleyn)

in examination 60% of the candidates passed. the number of candidate who passed was 240... (answered by ewatrrr)

35 out of 80 male candidates and 25 out of 60 female candidates who took a recruitment... (answered by stanbon)

I have two questions that I am in dire need of answers to. I have been stumped for 3... (answered by scott8148)

Candidates for employment at a city fire department are required to take a written... (answered by ewatrrr)

Students who graduate from law schools must still pass a bar exam before becoming... (answered by ewatrrr)