# Statistical Distribution functions¶

## CHIDIST¶

CHIDIST() returns the one-tailed probability of the chi2 distribution. The chi2 distribution is associated with a chi2 test.

`CHIDIST(value, degrees_freedom)`

Return data type: number

Argument Description
value The value at which you want to evaluate the distribution. The value must not be negative.
degrees_freedom A positive integer stating the number of degrees of freedom.

This function is related to the CHIINV function in the following way: If prob = CHIDIST(value,df), then CHIINV(prob, df) = value

Limitations: All arguments must be numeric, else NULL will be returned.

Example Result
CHIDIST(8, 15) Returns 0.9238

## CHIINV¶

CHIINV() returns the inverse of the one-tailed probability of the chi2 distribution.

`CHIINV(prob, degrees_freedom)`

Return data type: number

Argument Description
prob A probability associated with the chi2 distribution. It must be a number between 0 and 1.
degrees_freedom An integer stating the number of degrees of freedom.

This function is related to the CHIDIST function in the following way: If prob = CHIDIST(value,df), then CHIINV(prob, df) = value

Limitations: All arguments must be numeric, else NULL will be returned.

Example Result
CHIINV(0.9237827, 15) Returns 8.0000

## FDIST¶

FDIST() returns the F-probability distribution.

`FDIST(value, degrees_freedom1, degrees_freedom2)`

Return data type: number

Argument Description
value The value at which you want to evaluate the distribution. Value must not be negative.
degrees_freedom1 A positive integer stating the number of numerator degrees of freedom.
degrees_freedom2 A positive integer stating the number of denominator degrees of freedom.

This function is related to the FINV function in the following way: If prob = FDIST(value, df1, df2), then FINV(prob, df1, df2) = value

Limitations: All arguments must be numeric, else NULL will be returned.

Example Result
FDIST(15, 8, 6) Returns 0.0019

## FINV¶

FINV() returns the inverse of the F-probability distribution.

`FINV(prob, degrees_freedom1, degrees_freedom2)`

Return data type: number

Argument Description
prob A probability associated with the F-probability distribution and must be a number between 0 and 1.
degrees_freedom An integer stating the number of degrees of freedom.

This function is related to the FDIST function in the following way: If prob = FDIST(value, df1, df2), then FINV(prob, df1, df2) = value

Limitations: All arguments must be numeric, else NULL will be returned.

Example Result
FINV(0.0019369, 8, 6) Returns 15.0000

## NORMDIST¶

NORMDIST() returns the cumulative normal distribution for the specified mean and standard deviation. If mean = 0 and standard_dev = 1, the function returns the standard normal distribution.

`NORMDIST(value, mean, standard_dev)`

Return data type: number

Argument Description
value The value at which you want to evaluate the distribution.
mean A value stating the arithmetic mean for the distribution.
standard_dev A positive value stating the standard deviation of the distribution.

This function is related to the NORMINV function in the following way: If prob = NORMDIST(value, m, sd), then NORMINV(prob, m, sd) = value

Limitations: All arguments must be numeric, else NULL will be returned.

Example Result
NORMDIST(0.5, 0, 1) Returns 0.6915

## NORMINV¶

NORMINV() returns the inverse of the normal cumulative distribution for the specified mean and standard deviation.

`NORMINV(prob, mean, standard_dev)`

Return data type: number

Argument Description
prob A probability associated with the normal distribution. It must be a number between 0 and 1.
mean A value stating the arithmetic mean for the distribution.
standard_dev A positive value stating the standard deviation of the distribution.

This function is related to the NORMDIST function in the following way: If prob = NORMDIST(value, m, sd), then NORMINV(prob, m, sd) = value

Limitations: All arguments must be numeric, else NULL will be returned.

Example Result
NORMINV(0.6914625, 0, 1) Returns 0.5000

## TDIST¶

TDIST() returns the probability for the Student's t-distribution where a numeric value is a calculated value of t for which the probability is to be computed.

`TDIST(value, degrees_freedom, tails)` Return data type: number

Argument Description
value The value at which you want to evaluate the distribution and must not be negative.
degrees_freedom A positive integer stating the number of degrees of freedom.
tails Must be either 1 (one-tailed distribution) or 2 (two-tailed distribution).

This function is related to the TINV function in the following way: If prob = TDIST(value, df ,2), then TINV(prob, df) = value

Limitations: All arguments must be numeric, else NULL will be returned.

Example Result
TDIST(1, 30, 2) Returns 0.3253

## TINV¶

TINV() returns the t-value of the Student's t-distribution as a function of the probability and the degrees of freedom.

`TINV(prob, degrees_freedom)`

Return data type: number

Argument Description
prob A two-tailed probability associated with the t-distribution. It must be a number between 0 and 1.
degrees_freedom An integer stating the number of degrees of freedom.

All arguments must be numeric, else NULL will be returned.

This function is related to the TDIST function in the following way: If prob = TDIST(value, df ,2), then TINV(prob, df) = value.

Example Result
TINV(0.3253086, 30) Returns 1.0000