Page 171 - Probability Demystified

160 CHAPTER 9 The Normal Distribution

ANSWERS

1. The required area is shown in Figure 9-5.

Fig. 9-5.
Probability ¼ 0.341 þ 0.341 þ 0.136 þ 0.023 ¼ 0.841 or 84.1%

2. The required area is shown in Figure 9-6.

Fig. 9-6.
Probability ¼ 0.023 þ 0.136 ¼ 0.159 or 15.9%
3. The required area is shown in Figure 9-7.

Fig. 9-7.
Probability ¼ 0.023 þ 0.136 þ 0.341 þ 0.341 þ 0.136 ¼ 0.977 or 97.7%