Documented newly implemented statistical functions

Author: ushasundarajan

WindowsForms/Calculation-Engine/Supported-Formulas/statistical.md

@@ -2574,3 +2574,93 @@ _LINEST(known_y's, [known_x's], [const], [stats]))_
 *  If const is `FALSE`, b is set equal to 0 
 
 * stats (Optional). This is a logical value specifying whether to return additional regression statistics.
+
+## GAUSS     
+
+`GAUSS` function calculates the probability that a member of a standard normal population will fall between the mean and z standard deviations from the mean.
+
+**Syntax:**
+
+_GAUSS(z)_ 
+
+**where:**
+
+* z : The number of standard deviations away from the mean of the standard normal distribution. A positive z value indicates that the data point is above the mean, while a negative z value indicates that it is below the mean.
+
+**Remarks:**
+
+* If z is not a valid number, GAUSS returns the `#NUM!` error value.
+
+* If z is not a valid data type, GAUSS returns the `#VALUE!` error value.
+
+* Because NORM.S.DIST(0,True) always returns 0.5, GAUSS(z) will always be 0.5 less than NORM.S.DIST(z,True).
+
+## GAMMA
+
+`GAMMA` function returns the gamma function value for a given number.
+
+**Syntax:**
+
+_GAMMA(number)_
+
+**where:**
+
+* Number: The value for which is used to calculate the gamma function.
+
+**Remarks:**
+
+* `GAMMA` uses the following equation: Γ(N+1)=N×Γ(N).
+
+* If Number is a negative integer or 0, `GAMMA` returns the `#NUM!` error value.
+
+* If Number contains characters that are not valid, `GAMMA` returns the `#VALUE!` error value.
+
+## VAR.S
+
+The `VAR.S` function estimates the variance based on a sample of a population, ignoring logical values and text within the sample.
+
+**Syntax:**
+
+_VAR.S(number1, [number2], ... )_
+
+**where:**
+
+* Number1: Required. The first number argument corresponding to a sample of a population.
+
+* Number2, ...: Optional. Additional number arguments, up to 254, that correspond to a sample of a population.
+
+**Remarks:**
+
+* `VAR.S` assumes that its arguments represent a sample of the population. If your data represents the entire population, use the `VAR.P` function instead.
+
+* Arguments can be numbers or names, arrays, or references that contain numbers.
+Logical values and text representations of numbers that are typed directly into the list of arguments are counted.
+
+* If an argument is an array or reference, only numbers within that array or reference are counted; empty cells, logical values, text, or error values are ignored.
+
+* Arguments that are error values or text that cannot be translated into numbers will cause errors.
+To include logical values and text representations of numbers in a reference as part of the calculation, use the `VARA` function.
+
+## FREQUENCY
+
+The `FREQUENCY` function calculates how often values occur within a range of values and returns a vertical array of numbers representing the frequency distribution.
+
+**Syntax:**
+
+_FREQUENCY(data_array, bins_array)_
+
+**where:**
+
+* data_array: An array or reference to a set of values for which you want to count frequencies.
+
+* bins_array: An array or reference to intervals into which you want to group the values in data_array.
+
+**Remarks:**
+
+* The `FREQUENCY` function returns an array with one more element than the number of elements in bins_array. The extra element represents the count of values in data_array that are greater than the highest value in bins_array.
+
+* If data_array contains no values, `FREQUENCY `returns an array of zeros.
+
+* If bins_array contains no values, `FREQUENCY` returns the total number of elements in data_array.
+
+* `FREQUENCY` ignores blank cells and text in data_array.