A fair coin is tossed 3 times. Let X be the number of heads obtained. Find E(X) and V(X).

Explanation

To solve the problem of finding the expected value \( E(X) \) and variance \( V(X) \) of the random variable \( X \), which represents the number of heads obtained when a fair coin is tossed three times, we can follow these steps:

### Step 1: Determine the Sample Space
When a fair coin is tossed three times, the total number of outcomes is given by \( 2^3 = 8 \). The sample space consists of the following outcomes:
- HHH (3 heads)
- HHT (2 heads, 1 tail)
- HTH (2 heads, 1 tail)
- THH (2 heads, 1 tail)
...