kNormal Probability Distribution Calculation

You can calculate normal probability distributions for single-variable statistics with the Run-Matrixmode.

Press K6(g)3(PROB)6(g) to display a function menu, which contains the following items.

{P(}/{Q(}/{R(} ... obtains normal probability {P(t)}/{Q(t)}/{R(t)} value

{t(} ... {obtains normalized variate t(x) value}

Normal probability P(t), Q(t), and R(t), and normalized variate t(x) are calculated using the following formulas.

Standard Normal Distribution

 

P (t)

 

 

Q (t)

R (t)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0 t

 

0 t

 

0 t

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

σx

 

 

 

 

 

 

Example

The following table shows the results of measurements of the height of

 

20 college students. Determine what percentage of the students fall in

 

the range 160.5 cm to 175.5 cm. Also, in what percentile does the 175.5

 

cm tall student fall?

Class no.

Height (cm)

Frequency

 

 

 

1

158.5

1

2

160.5

1

3

163.3

2

4

167.5

2

 

 

 

5

170.2

3

Class no.

Height (cm)

Frequency

6

173.3

4

 

 

 

7

175.5

2

8

178.6

2

9

180.4

2

10

186.7

1

 

 

 

6-27