Answer
P(x<-1.401) = 0.080757
Steps Explained:
Given X = 240, μ = 250, and σ = 7.14
Calculate P(X < Z)
Z-score formula
Using the Normal Distribution, Calculate P(X < 240)
| Z = | X - μ |
| σ/√1 |
| Z = | 240 - 250 |
| 7.14/√1 |
| Z = | -10 |
| 7.14/1 |
| Z = | -10 |
| 7.14 |
Z = -1.401
From the table below, we see that our Z value is = 0.419243
Z-table Lookup Value
The z-table probability runs from 0 to z and -z to 0
Z value = 0.419243
Since that represents ½ of the graph, we subtract our value from 0.5 → 0.5 - 0.419243
P(x<-1.401) = 0.080757
Final Answer
P(x<-1.401) = 0.080757Related Calculators: Negative Binomial Distribution | Geometric Distribution | Binomial Distribution