The Essentials of Biostatistics for Physicians, Nurses, and Clinicians

60 CHAPTER 5 Estimating Means and Proportions

Figure 5.1. Binomial distribution n = 12, p = 1/3. Note that the number of successes is
1less than the number displayed on the x - axis. So 1 corresponds to 0 successes, 2
corresponds to 1 success, 3 corresponds to 2 successes,... , 13 corresponds to 12
successes.

0

0.05

0.1

0.15

0.2

0.25

0.3

1 2 3 4 5 6 7 8 9 10 11 12 13

Number of Successes +1

Probability

Figure 5.2. Poisson distribution with lambda = 0.87. Note that the number of events is
1 less than the number displayed on the x - axis. So 1 corresponds to 0 events, 2
corresponds to 1 event and so on.

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

1234567 89

Number of Events +1

Probability