  ## Some Simple Excel Functions

There are many, many Excel functions available, but initially the following functions might prove useful:

Some of the following are functions that take a range, like $C3:C7$ or something similar. For the examples discussed below, we use $R$ and $R_i$ to denote ranges of cells. Further, for the purpose of making sense of the example calculations, let us suppose some specific $R_i$ ranges are filled with the following:

$$R_1 : \{4,6,7,-3\}, \quad \quad R_2 : \{6,8,-5,7\}, \quad \quad R_3 : \{5, \textrm{""}, \textrm{"A"}, 6, -1\}$$
ABS(x)

Absolute value of $x$

SQRT(x)

Square Root of $x$

SUM($R$)

Sum of the elements in range $R$. Example:
$\textrm{SUM}(R_1) = 4 + 6 + 7 - 3 = 14$

AVERAGE($R$)

Average of the elements in range $R$. Example:
$\textrm{SUM}(R_1) = (4 + 6 + 7 - 3) / 4 = 3.5$

SUMSQ($R$)

Sum of the squares of the elements in range $R$. Example:
$\textrm{SUMSQ}(R_1) = 4^2 + 6^2 + 7^2 + (-3)^2 = 110$

PRODUCT($R$)

Product of elements in range $R$. Example:
$\textrm{PRODUCT}(R_1) = 4 \cdot 6 \cdot 7 \cdot (-3) = -504$

COUNT($R$)

Count of numeric elements in range $R$. Example:
$\textrm{COUNT}(R_3) = 3$

COUNTA($R$)

Count of non-empty elements in range $R$. Example:
$\textrm{COUNTA}(R_3) = 4$