CALC 1 Probabilities Calculator
This calculator focuses on common probability distributions and functions.
Shifted Keys:
Keystrokes "= or ENTER": use = in Chain calculation mode, ENTER in RPN calculation mode.
When using Algebraic calculation mode, many of these keys will insert the function.
For more distruibutions, see the Statistical Distributions Overview.
Φ(x) key, the standard normal distribution CDF.
| Value | Keystrokes | Display | Description |
|---|---|---|---|
| 1 | Φ(x) | 0.841 | Calculates the standard normal distribution CDF |
Φ⁻¹(p) key, the inverse standard normal distribution CDF.
| Value | Keystrokes | Display | Description |
|---|---|---|---|
| .95 | shift Φ⁻¹(p) |
1.64 | Calculates the inverse standard normal distribution CDF. |
Φ 2t(x) key, the standard normal distribution CDF for 2 tails.
| Value | Keystrokes | Display | Description |
|---|---|---|---|
| 2 | shift Φ 2t(x) |
0.954 | Calculates the standard normal distribution CDF for 2 tails. |
Φ⁻¹2t(p) key, the inverse standard normal distribution CDF for 2 tails.
| Value | Keystrokes | Display | Description |
|---|---|---|---|
| .95 | shift Φ⁻¹2t(p) |
1.96 | Calculates the inverse standard normal distribution CDF for 2 tails. |
t(x,df) key, the t distribution CDF.
| Value | Keystrokes | Display | Description |
|---|---|---|---|
| 2 | = or ENTER | 2.00 | Enters the X value | 5 | t(x,df) | 0.949 | Enters the df value, then calculates the t distribution CDF. |
t⁻¹(p,df) key, the inverse t distribution CDF.
| Value | Keystrokes | Display | Description |
|---|---|---|---|
| .95 | = or ENTER | 0.950 | Enters the p value | 5 | shift t⁻¹(p,df) |
2.02 | Enters the df value, then calculates the inverse t distribution CDF. |
t 2t(p,df) key, the t distribution CDF for 2 tails.
| Value | Keystrokes | Display | Description |
|---|---|---|---|
| 2 | = or ENTER | 2.00 | Enters the X value | 5 | shift t 2t(p,df) |
0.898 | Enters the df value, then calculates the t distribution CDF for 2 tails. |
t(x,df) key, the inverse t distribution CDF for 2 tails.
| Value | Keystrokes | Display | Description |
|---|---|---|---|
| .95 | = or ENTER | 0.950 | Enters the p value | 5 | shift t⁻¹2t(p,df) |
2.57 | Enters the df value, then calculates the inverse t distribution CDF for 2 tails. |
χ²(x,df) key, the Chi-Squared Distribution CDF.
| Value | Keystrokes | Display | Description |
|---|---|---|---|
| 2 | = or ENTER | 2.00 | Enters the X value | 5 | χ²(x,df) | 0.151 | Enters the df value, then calculates the Chi-Squared distribution CDF. |
χ²⁻¹(p,df) key, the inverse Chi-Squared distribution CDF.
| Value | Keystrokes | Display | Description |
|---|---|---|---|
| .95 | = or ENTER | 0.95 | Enters the p value | 5 | shift χ²⁻¹(p,df) |
11.1 | Enters the df value, then calculates the inverse Chi-Squared distribution CDF. |
nCr key, the combinations of n items taken r at a time.
| Value | Keystrokes | Display | Description |
|---|---|---|---|
| 52 | = or ENTER | 52.0 | Enters the n value | 5 | nCr | 2,598,960 | Enters the r value, then calculates combinations of n items taken r at a time. |
nPr key, the permutations of n items taken r at a time.
| Value | Keystrokes | Display | Description |
|---|---|---|---|
| 52 | = or ENTER | 52.0 | Enters the n value | 5 | shift nPr |
311,875,200 | Enters the r value, then calculates the permutations of n items taken r at a time. |
Γ key, the gamma function.
| Value | Keystrokes | Display | Description |
|---|---|---|---|
| 5 | Γ | 24 | Calculates the gamma function. |
ln Γ key, the gamma function.
| Value | Keystrokes | Display | Description |
|---|---|---|---|
| 5 | shift ln Γ |
3.18 | Calculates the natural log of the gamma function. |
1-x key
This key is a quick calculation of p values to convert form lower to upper tail.
| Value | Keystrokes | Display | Description |
|---|---|---|---|
| 0.95 | 1 - x | .05 | Calculates 1 - x. |
rand key, Returns a pseudo-random number between 0 and <1.
rand(x,y) key, returns a random number between x and y.
| Value | Keystrokes | Display | Description |
|---|---|---|---|
| 52 | = or ENTER | 52.0 | Enters the y value | 1 | rand(x,y) | A random number from 1 - 52. | Enters the x value, then returns a random number between x and y. |
To repeat, press the ROLL key to roll the x and y values down, then press rand(x,y).
The minimum and maximum values can be in any order.