In: Statistics and Probability
Complete parts (a) and (b) below. The number of dogs per household in a small town
Dogs 0 1 2 3 4 5
Probability 0.649 0.220 0.087 0.024 0.013 0.008
(a) Find the mean, variance, and standard deviation of the probability distribution.
Solution
x | P(x) | x * P(x) | x2 * P(x) |
0 | 0.649 | 0 | 0 |
1 | 0.22 | 0.22 | 0.22 |
2 | 0.087 | 0.174 | 0.348 |
3 | 0.024 | 0.072 | 0.216 |
4 | 0.013 | 0.052 | 0.208 |
5 | 0.008 | 0.04 | 0.2 |
1.001 | 0.558 | 1.192 |
a) Mean = = X * P(X) = 0.558
b ) Variance = 2 =X 2 * P(X) - 2
=1.192 - 0.31136
= 0.881
Variance = 0.881
c ) Standard deviation = =X 2 * P(X) - 2
=1.192 - 0.31136
=0.881
= 0.938
Standard deviation = 0.938