SOLUTION: construct the probability distribution describing the experiment of rolling a pair of dice 3 times, and counting as x the number of time a total of 9 is rolled. then find the mean

Algebra ->  Probability-and-statistics -> SOLUTION: construct the probability distribution describing the experiment of rolling a pair of dice 3 times, and counting as x the number of time a total of 9 is rolled. then find the mean       Log On


   



Question 612276: construct the probability distribution describing the experiment of rolling a pair of dice 3 times, and counting as x the number of time a total of 9 is rolled. then find the mean and standard deviation of the distribution.
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
construct the probability distribution describing the experiment of rolling a pair of dice 3 times, and counting as x the number of time a total of 9 is rolled. then find the mean and standard deviation of the distribution.
----
Sketch the sample space of 6*6 = 36 sums
-----
Count the # of sums not adding up to nine and the number adding up to 9.
x = 0 ; 32 times ; probability = 32/36 = 8/9
x = 1 ; 4 times : probability = 4/36 = 1/9
----
mean = np = (1/9)*36 = 4
std = sqrt(npq) = sqrt(4*8/9) = 1.8856
=====================
Cheers,
Stan H.