Essential Statistics

671 / 762

Chapter 15: Chi-Square Tests 671
Figure 15-9: Binomial Probabilities for Example 15.3
So if we let X = number of sixes rolled, then P ( X = 0) = 0.5787,
P (X = 1) = 0.3472, P(X = 2) = 0.0694, and P (X = 3) = 0.0046.
Multiplying 200 by these probabilities will give the expected number of
sixes rolled. Thus,
E ( X = 0) = 2000.5787 = 115.74
E ( X = 1) = 2000.3472 = 69.44
E( X = 2) = 2000.0694 = 13.88
E ( X = 3) = 2000.0046 = 0.92
Table 15-2 summarizes the information so far.