Download Section 5.3 Finding Values

Section 5.3 Finding Values
Find the z-score that corresponds to the given cumulative area or percentile.
Area = 0.9099
Area = 0.0192
P30
P82
Find the z-score that has 12.1% of
the distribution’s area to its right.
Find the z score for which 40% of the
distribution’s area lies between –z and z
In these examples you are given probabilities and are asked to find x values.
If the average price of a new home is normally distributed with a mean of $145,000, and
standard deviation $1500, what price represents the 78th percentile?
A mandatory competency test for high school sophomores has a normal distribution with a
mean of 400 and a standard deviation of 100.
a) The top 3% of students receive $500. What is the cutoff score for receiving this
award?
b) The bottom 1.5% of students must go to summer school. What is the
minimum score needed to stay out of this group?