Reliability Engineering Handbook, Volume 1

For z ? 3.0, entries are in abbreviated notation . - p, where
1 - F( z) = . 10 -p.
X is normally distributed with mean ? = 27 and standard deviation ? = 4. What is the probability X will exceed 41?
Answer: z = (41 - 27)/4 = 3.50,
P( X ? 41) =1 - F(3.50),
= 2.3263 10 -4 = 0.00023263.
From Example 1, what is the probability that X will be less than 41?
P( X < 41) = 1 - [1 - F(3.50)],
= 1 - 0.00023263,
= 0.99976737.
| z | 1 - F( z) | z | 1 - F( z) | z | 1 - F( z) | z | 1 - F( z) |
|---|---|---|---|---|---|---|---|
| 0.00 | 0.50000 | 0.40 | 0.34458 | 0.80 | 0.21186 | 1.20 | 0.11507 |
| 0.01 | 0.49601 | 0.41 | 0.34090 | 0.81 | 0.20897 | 1.21 | 0.11314 |
| 0.02 | 0.49202 | 0.42 | 0.33724 | 0.82 | 0.20611 | 1.22 | 0.11123 |
| 0.03 | 0.48803 | 0.43 | 0.33360 | 0.83 | 0.20327 | 1.23 | 0.10935 |
| 0.04 | 0.48405 | 0.44 | 0.32997 | 0.84 | 0.20045 | 1.24 | 0.10749 |
| 0.05 | 0.48006 | 0.45 | 0.32636 | 0.85 | 0.19766 | 1.25 | 0.10565 |
| 0.06 | 0.47608 | 0.46 | 0.32276 | 0.86 | 0.19489 | 1.26 | 0.10383 |
| 0.07 | 0.47210 | 0.47 | 0.31918 | 0.87 | 0.19215 | 1.27 | 0.10204 |
| 0.08 | 0.46812 | 0.48 | 0.31561 | 0.88 | 0.18943 | 1.28 | 0.10027 |
| 0.09 | 0.46414 | 0.49 | 0.31207 | 0.89 | 0.18673 | 1.29 | 0.098525 |
| 0.10 | 0.46017 | 0.50 | 0.30854 | 0.90 | 0.18406 | 1.30 | 0.096800 |
| 0.11 | 0.45620 | 0.51 | 0.30503 | 0.91 | 0.18141 | 1.31 | 0.095093 |
| 0.12 | 0.45224 |