The means of five observations is 4 and their variance is 5.2. If three of these observations are 1,2 and 6, then the other two are 2 and 9                          (b)  3 and 8 4 and 7                          (d)  5 and 6

Options

A. 2 and 9
B. 3 and 8
C. 4 and 7
D. 5 and 6

Explanation

To solve the problem, we need to find the two unknown observations given that the mean of five observations is 4 and their variance is 5.2. We know three of the observations: 1, 2, and 6.

### Step-by-Step Solution:

1. **Understanding the Mean**:
The mean of five observations is given by:
\[
\text{Mean} = \frac{\text{Sum of observations}}{\text{Number of observations}}
...