Section 6: Functions continue102
Again, as in the use of MEAN , the easiest way to accumulate the required data in the statistical registers is by using the Σ+ function.
Example: Below is a chart of monthly maximum and minimum winter (October-March) rainfall for a 79-year period in Corvallis, Oregon. What are the average maximum and minimum rainfalls and the standard deviation of the maximum and minimum rainfalls? Rainfall amounts are given in inches.
 
   
  October November December January February March
Maximum  
 
9.70  
18.28  
14.47  
15.51  
15.23  
11.70  
Minimum  
 
0.10  
0.22  
2.33  
1.99  
0.12  
0.43  
Keystrokes Display    
g CLΣ 
  0.0000    
  Clears the statistical registers (still defined as R11 through R16).
9.7 ENTER  
  9.7000    
   
.10 Σ+ 
  1.0000    
  First entry. Number of data pairs is now 1.
18.28 ENTER  
  18.2800    
   
.22 Σ+ 
  2.0000    
  Second entry. Number of pairs is now 2.
14.47 ENTER  
  14.4700    
   
2.33 Σ+ 
  3.0000    
   
15.51 ENTER  
  15.5100    
   
1.99 Σ+ 
  4.0000    
   
15.23 ENTER  
  15.2300    
   
.12 Σ+ 
  5.0000    
   
11.70 ENTER  
  11.7000    
   
.43 Σ+ 
  6.0000    
  Number of pairs is now 6 (n = 6).