Variance is another measure that indicates how spread out the values are.
In fact, taking the square root of the variance gives the standard deviation, and conversely, multiplying the standard deviation by itself gives the variance.
We will use a data set with 10 observations to demonstrate how to calculate the variance:
|
Duration |
Average_Pulse |
Max_Pulse |
Calorie_Burnage |
Hours_Work |
Hours_Sleep |
|
30 |
80 |
120 |
240 |
10 |
7 |
|
30 |
85 |
120 |
250 |
10 |
7 |
|
45 |
90 |
130 |
260 |
8 |
7 |
|
45 |
95 |
130 |
270 |
8 |
7 |
|
45 |
100 |
140 |
280 |
0 |
7 |
|
60 |
105 |
140 |
290 |
7 |
8 |
|
60 |
110 |
145 |
300 |
7 |
8 |
|
60 |
115 |
145 |
310 |
8 |
8 |
|
75 |
120 |
150 |
320 |
0 |
8 |
|
75 |
125 |
150 |
330 |
8 |
8 |
| Tip: Variance is commonly represented by the symbol Sigma squared: σ². |
