Use the fact that the mean of a geometric distribution is u = - and the variance is o2 9
2
1
A daily number lottery chooses two balls numbered 0 to 9. The probability of winning the lottery is Let x be the
100
number of times you play the lottery before winning the first time.
(a) Find the mean, variance, and standard deviation. (b) How many times would you expect to have to play the lottery
before winning? It costs $1 to play and winners are paid $900. Would you expect to make or lose money playing this
lottery? Explain.
(a) The mean is - (Type an integer or a decimal.)
The variance is (Type an integer or a decimal.)
The standard deviation is I
(Round to one decimal place as needed.)
(b) You can expect to play the game times before winning
Would you expect to make or lose money playing this lottery? Explain.
times you play. So the net
O A. You would expect to lose money. On average you would win $900 once in every
gain would be $
O B. You would expect to make money. On average you would win $900 once in every
gain would be $
times you play. So the net