Introduction
Grouped data are presented in frequency distributions rather than entering each observation individually. Given a set of data points:
X1, X2, . . . , Xn,
with respective frequencies:
f1, f2, . . . , fn,
this procedure computes the mean, standard deviation, and standard error of the mean.
Instructions
Follow these steps to compute the mean, standard deviation, and standard error of the mean:
- Press f, then CLEAR [REG].
- Key in the first value and press ENTER twice.
- Key in the respective frequency and press STO, [+], 0, [X], then Sigma +. The display shows the number of data points entered.
- Repeat steps 2 and 3 for each data point.
- To calculate the mean (average) press RCL, 0, STO, 1, RCL, 6, STO, 3, g, then x-mean (the zero key).
- Press g, then s to find the standard deviation
- Press RCL, 0, g, the Square Root key, then the Divide key to find the standard error of the mean.
Example
A survey of 266 one-bedroom apartment rentals reveals that 54 rent for $190 per month, 32 rent for $195 per month, 88 rent for $200 per month, and 92 rent for $206 per month. What are the average monthly rental, the standard deviation, and the standard error of the mean?
Keystrokes | Display | Comments |
---|---|---|
f, CLEAR [REG], 190, ENTER, ENTER, 54, STO, [+], 0, [X],then Sigma + | 1.00 | Calculator cleared and first data point entered |
195, ENTER, ENTER, 32, STO, [+], 0, [X], then Sigma + | 2.00 | Second data point entered |
200, ENTER, ENTER, 88, STO, [+], 0, [X], then Sigma + | 3.00 | Third data point entered |
206, ENTER, ENTER, 92, STO, [+], 0, [X], then Sigma + | 4.00 | Fourth data point entered |
RCL, 0, STO, 1, RCL, 6, STO, 3, g, then x-mean | 199.44 | Average monthly rent. |
g, then s | 5.97 | Standard Deviation |
RCL, 0, g, square root, then divide | 0.37 | Standard Error of the mean |
Updated On: 12.07.14