Question

a fair die is rolled 30 times. find the mean of the probability distribution of the number of 5s obtained for this experiment.

Answer 1

5/30 should be the probability.

Answer 2

Answer:

5

Step-by-step explanation:

Let X be the number of 5s obtained in 30 rolls.

Here we have n=30 trials, and the probability of "success" (i.e. getting a 5) in each trial is p=1/6.  So X, which counts successes, is binomially distributed:

   X ∼ B( 30, 1/6 )

The mean of a binomial distribution B(n,p) is given by np.

Thus, the mean for X's distribution is

  np = 30 × 1/6 = 30/6 = 5