the numbers of dogs per household in a small town dogs proba

the numbers of dogs per household in a small town

dogs probability

0 0.662

1 0.209

2 0.084

3 0.024

4 0.014

5 0.006

find the mean of the probability ( round to one decimal place)

find the variance of the probability distrubition (round to one decimal place

find the standard deviation of the probability distrubution (round to one decimal place)

Solution

a) mean , E(X) = 0 * 0.662 + 1 * 0.209 + 2 * 0.084 + 3 * 0.024 + 4 * 0.014 + 5 * 0.006

                         = 0.535        (ANS)

b) E(X²) = 0² * 0.662 + 1² * 0.209 + 2² * 0.084 + 3² * 0.024 + 4² * 0.014 + 5² * 0.006

             = 1.135

var(X) = E(X²) - (E(X))² = 1.135 - 0.535²

                                      = 0.849    (ANS)

c) standard deviation = sqrt(0.849) = 0.921   (ANS)