6-27
k Normal Probability Distribution Calculation
  You can calculate normal probability distributions for single-variable statistics with the 
 Run-Matrix  mode.
  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
   
  
  
  
  
  
  
  
  
  
  
  
  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 
P
 
(
t
)Q
 
(
t
)R
 
(
t
)
tt t
00 0
σ
x
P
 
(
t
)Q
 
(
t
)R
 
(
t
)
tt t
00 0
σ
x
 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