User Guide

Chapter 13: Inferential Statistics and Distributions 217
If the height distribution among a population of women is normally distributed with a mean m of
165.1 centimeters and a standard deviation s of 6.35 centimeters, what height is exceeded by only
5 percent of the women (the 95th percentile)?
The result is displayed on the home screen; it shows that five percent of the women are taller than
175.5 centimeters.
Now graph and shade the top 5 percent of the population.
2. Press †
163 Ë 8 Í to store 163.8 to v.
Press
7 Ë 1 Í to store 7.1 to Sx.
Press
90 Í to store 90 to n.
3. Press † to move the cursor onto
Calculate, and
then press Í to calculate the new 99 percent
confidence interval. The results are displayed on
the home screen.
4. Press ‘ to clear the home screen.
Press y = to display the
DISTR
(distributions) menu.
5. Press
3 to open the invNorm( wizard. Enter the
information as follows:
Press Ë
95 †165 Ë 1 † 6 Ë 35 † (95 is the
area, 165.1 is m, and 6.35 is s).
6. Press Í to paste the function and Í again
to calculate the result.
7. Press p and set the window variables to
these values.
Xmin=145 Ymin=L.02 Xres=1
Xmax=185 Ymax=.08
Xscl=5 Yscl=0