Creating a new column

You can calculate new columns based on old ones in Minitab. The LET command in Minitab is used to calculate a column. The syntax is this:

MTB> LET column= arithmetic expression

The following example calculates the improvement from TEST1 to TEST4.


Since C5 and C2 are named, we could have also done this:


Arithmetic operators include +, -, * (for multiply), / (for divide), and ** (for exponentiation). Also parenthesis can be used to clarify complex operations. The following example calculates column 7 as the square of column 6.

MTB> LET C7= C6**2

Rowwise statistical functions can also be used to compute a statistic across a series of columns, and to put the result in the corresponding locations of the new column. The following example computes C8 as the mean of C2 to C5.


More complex operations are possible. The following example would compute a weighted mean if the first three tests were worth 50% of the grade and the final test were worth 50% of the grade.

MTB> LET C8=(.50*((C2+C3+C4)/3))+(.50*C5)

The following are MINITAB rowwise statistics.

RCOUNT col-col resultcol -- gives the count of values in the row.
RN col-col resultcol -- gives the number of non-missing values across the row.
RNMISS col-col resultcol -- gives the number of missing values across the row.
RSUM col-col resultcol -- gives the sum of the values across the row.
RMEAN col-col resultcol -- gives the mean of the values across the row.
RSTDEV col-col resultcol -- gives the standard deviation of the values across the row.
RMEDIAN col-col resultcol -- gives the median of the values.
RMINIMUM col-col resultcol -- gives the minimum value across the row.
RMAXIMUM col-col resultcol -- gives the maximum value across the row.
RSSQ col-col resultcol -- gives the uncorrected sum of squares.

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