Question

Assume the random variable X is normally distributed, with mean of 58 and standard deviation of 7. Find the 9th percentile.

The 9th percentile is:

Find the Z-scores that separate the middle 82% of the distribution from the area in the tails of the standard normal distribution.

The Z-scores are:

Answer 1

1)

for 9th percentile critical value of z=		-1.34
therefore corresponding value=mean+z*std deviation=			48.62

2)

for middle 82 percentile; z score =-1.34 ; 1.34