In: Statistics and Probability
(4 pts) The Graduate Record Examination (GRE) is a test required for admission to many U.S. graduate schools. Students' scores on the quantitative portion of the GRE follow a normal distribution with mean 150 and standard deviation 8.8. In addition to other qualifications, a score of at least 160 is required for admission to a particular graduate school.
Suppose n = 16 randomly selected students take the GRE on the same day.
Solution :
Given that ,
mean = = 150
standard deviation = = 8.8
n = 16
Shape is approximately normal .
= 150 and
= / n = 8.8 / 16 = 8.8 / 4 = 2.2
P( < 147) = P(( - ) / < (147 - 150) / 2.2)
= P(z < -1.36)
Using standard normal table,
= 0.0869
Probability = 0.0869
Probability > 0.05
Outcome is not unusual .