3.Repeat step 2 for each new case.
Example: Find Q(x) for x = 1.18 and x = 2.1.
KeystrokesDisplay
1.18 | 0.12 | Q(1.18) |
|
| |
2.1 | 0.02 | Q(2.1) |
|
|
Covariance
Covariance is a measure of the interdependence between paired variables (x and y). Like standard deviation, covariance may be defined for either a sample (Sxy) or a population (S'xy) as follows:
Sxy = r * sx * sy S'xy = r * s'x * s'y
The following procedure finds the covariance of a sample (Sxy) and of a population (S'xy):
1.Press 
CLEAR 
.
2.Key in the 
.
3.Key in the 
. Repeat steps 2 and 3 for all data pairs.
4.Press 
to obtain the value of Sxy.
5.Press 
1 1 
1 
to obtain S'xy.
Example 1: Find the sample covariance (Sxy) and population covariance (S'xy) for the following paired variables:
| xi |
| 26 | 30 | 44 | 50 | 62 | 68 | 74 |
| |
| yi |
| 92 | 85 | 78 | 81 | 54 | 51 | 40 |
| |
|
|
|
|
|
|
|
|
|
|
| |
|
| Keystrokes |
|
| Display |
|
|
|
|
| |
CLEAR |
|
|
|
|
|
|
|
| |||
92 |
| 26 |
|
|
|
|
|
|
|
|
|
85 |
| 30 |
|
| 7.00 |
| Total number of entries. |
| |||
|
|
|
|
|
|
|
|
|
| ||
78 |
| 44 |
|
|
|
|
|
|
|
|
|
81 |
| 50 |
|
|
|
|
|
|
|
|
|
