Probability Functions |
Use these functions to compute and verify statistical measures such as significant probabilities, critical values of statistics, confidence intervals and histogram comparisons. |
Function |
Description |
normdist |
The cumulative
normal (or Gaussian) distribution function.
It returns the probability that a normal random
variable is less than a specified independent
variable value. |
norminv |
The inverse cumulative
normal (or Gaussian) distribution function.
The probability that a normally distributed
random variable is less than the return value
is equal to the argument you specify. |
normden |
The normal (or
Gaussian) probability density function. The
graph of this function is the familiar ?bell
curve?. It returns the value of the slope of
the cumulative distribution function at the
specified argument value. |
chisquaredist |
The cumulative
chi-square distribution function. It returns
the probability that a chi-square distributed
random variable is less than a specified independent
variable value. |
chisquareinv |
The inverse cumulative
chi-square distribution function. The probability
that a chi-square distributed random variable
is less than the return value is equal to the
argument you specify. |
chisquareden |
The chi-square
probability density function. It returns the
value of the slope of the cumulative distribution
function at the specified argument value. |
fdist |
The F-distribution
function. It returns the probability that an
F distributed random variable is less than
a specified independent variable value. |
finv |
The inverse F-distribution
function. The probability that an F-distributed
random variable is less than the return value
is equal to the argument you specify. |
fden |
The F-distribution?s
probability density function. It returns the
value of the slope of the cumulative distribution
function at the specified argument value. |
tdist |
The Student?s T-distribution
function. It returns the probability that a
T-distributed random variable is less than
a specified independent variable value. |
tinv |
The inverse of
Student?s T-distribution function. The probability
that a T-distributed random variable is less
than the return value is equal to the argument
you specify. |
tden |
The T-distribution?s
probability density function. It returns the
value of the slope of the cumulative distribution
function at the specified argument value. |
gammadist |
The cumulative
gamma distribution function. It returns the
probability that a gamma distributed random
variable is less than a specified independent
variable value. |
gammainv |
The inverse cumulative
gamma distribution function. The probability
that a gamma distributed random variable is
less than the return value is equal to the
argument you specify. |
gammaden |
The gamma distribution?s
probability density function. It returns the
value of the slope of the cumulative distribution
function at the specified argument value. |
weibulldist |
The cumulative
Weibull distribution function. It returns the
probability that a Weibull distributed random
variable is less than a specified independent
variable value. |
weibullinv |
The inverse cumulative
Weibull distribution function. The probability
that a Weibull distributed random variable
is less than the return value is equal to the
argument you specify. |
weibullden |
The Weibull distribution?s
probability density function. It returns the
value of the slope of the cumulative distribution
function at the specified argument value. |
cauchydist |
The cumulative
Cauchy distribution function. It returns the
probability that a Cauchy distributed random
variable is less than a specified independent
variable value. |
cauchyinv |
The inverse cumulative
Cauchy distribution function. The probability
that a Cauchy distributed random variable is
less than the return value is equal to the
argument you specify. |
cauchyden |
The Cauchy distribution?s
probability density function. It returns the
value of the slope of the cumulative distribution
function at the specified argument value. |
erf |
The error function.
It is related to the cumulative normal distribution
function by scaling and translation. |
erfc |
The complementary
error function. It returns one minus the return
value of the error function. |
lognormaldist |
The cumulative
log-normal distribution function. It returns
the probability that a log-normal random variable
is less than a specified independent variable
value. |
lognormalinv |
The inverse cumulative
log-normal distribution function. The probability
that a log-normal random variable is less than
the return value is equal to the argument you
specify. |
lognormalden |
The log-normal distribution's probability density function. It returns the value of the slope of the cumulative distribution function at the specified argument value. |
expdist |
The cumulative
exponential distribution function. It returns
the probability that an exponential random
variable is less than a specified independent
variable value. |
expinv |
The inverse cumulative
exponential distribution function. The probability
that an exponential random variable is less
than the return value is equal to the argument
you specify. |
expden |
The exponential
distribution?s probability density function.
It returns the value of the slope of the cumulative
distribution function at the specified argument
value. |
logisdist |
The cumulative
logistic distribution function. It returns
the probability that a logistic random variable
is less than a specified independent variable
value. |
logisinv |
The inverse cumulative
logistic distribution function. The probability
that a logistic random variable is less than
the return value is equal to the argument you
specify. |
logisden |
The logistic distribution?s
probability density function. It returns the
value of the slope of the cumulative distribution
function at the specified argument value. |
loglogisdist |
The cumulative
log-logistic distribution function. It returns
the probability that a log-logistic random
variable is less than a specified independent
variable value. |
loglogisinv |
The inverse cumulative
log-logistic distribution function. The probability
that a log-logistic random variable is less
than the return value is equal to the argument
you specify. |
loglogisden |
The log-logistic
distribution's probability density function.
It returns the value of the slope of the cumulative
distribution function at the specified argument
value. |