Let X be no. of selected scouts who are well trained in first aid.
Here random variable X may have value 0, 1, 2.
Now probability distribution table is
X |
0 |
1 |
2 |
P(X) |
38/245 |
120/245 |
87/245 |
Now mean E(X) = ∑pixi = 0 x 38/245 + 1 x 120/245 + 2 x 87/245 = (120 + 174)/245 = 294/245
A well trained scout should be disciplined