Calculates the normal distribution cumulative distribution function for the upper tail.
The cumulative normal distribution function describes probabilities for a random variable to fall in the intervals of the form (x, ∞].
If the mean speed of the vehicles on a road is 60 and the standard deviation is 4, what percent are going over 65?
Value | Keystrokes | Display | Description |
---|---|---|---|
65 | x | 65.0000 | Stores the x value. |
60 | μ | 60.0000 | Stores the mn (mean) value. |
4 | σ | 4.0000 | Stores the sd (standard deviation) value. |
cdf | 0.1056 | Calculates the cumulative distribution function. |
What speed are 0.05 of the vehicles going over?
These keystrokes assume the values from example 1.
Value | Keystrokes | Display | Description |
---|---|---|---|
.05 | cdf | 0.050 | Stores the cdf value. |
x | 66.58 | Calculates the x (inverse) value. |
To calculate the standard values forund in tables, use μ = 0 and σ = 1.
Reference:
Normal distribution - Wikipedia