The mean and standard deviation calculations are based upon the values accumulated in the statistical registers. These buttons are used to perform the calculations:

calculates and displays the mean (average) of the x values.

calculates and displays the mean (average) of the y values.

calculates and displays the weighted mean of the x values. The y values are used to determine the weight for the corresponding x value.

calculates the standard deviation of the x and y values and returns the results in the x and y registers, respectively.

calculates the population standard deviation of the x and y values and returns the results in the x and y registers, respectively.

Continuing the previous example,

Press to calculate the mean or average of the x values (61.25).

Press to calculate the mean or average of the y values (15.75).

Press to calculate the weighted mean of the x values (76.11).

Press to calculate and display the standard deviation of the x values (30.10).

Press to display the standard deviation of the y values (10.69).