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​ ​​ Identifying the Sample Standard Deviation

Previous research studies showed that the mean learning performance of college students is 64 out of 100 when they are presented with static illustrations along with textual information. A researcher is interested in whether using animations instead of static illustrations would increase learning performance. She collects data from 31 college students. The dataset can be found in the Excel file.

Based on the information above, which of the following is the sample standard deviation?

  • A. 7.4924
  • B. 6.5769
  • C. 4.4356
  • D. 7.71
  • E. 3.2448

The correct answer is B. 6.5769

Step-by-Step Guide to Calculate Standard Deviation in Excel:

  1. Input Your Data:
    • Enter your data values in a single column or row in Excel.
    • For example, if you have 10 data points, enter them in cells A1 through A10.
  2. Select the Cell for the Result:
    • Click on the cell where you want the standard deviation result to appear.
  3. Use the Standard Deviation Formula:
    • Excel provides different functions depending on the type of data:
      • =STDEV.P(range): Use this if your data represents the entire population.
      • =STDEV.S(range): Use this if your data is a sample of the population. This is the most commonly used formula.
      • =STDEVP(range): An older version of =STDEV.P, still available in older Excel versions.
      • =STDEV(range): An older version of =STDEV.S, still available in older Excel versions.
    • Replace "range" with the actual range of your data. For example, if your data is in cells A1 to A10, you would use A1:A10 as the range.
  4. Enter the Formula:
    • For a sample standard deviation, type: =STDEV.S(A1:A10) and press Enter.
    • For a population standard deviation, type: =STDEV.P(A1:A10) and press Enter.
  5. View the Result:
    • Excel will calculate and display the standard deviation in the cell where you entered the formula.

Example:

If you have data in cells A1 to A10, and you want to calculate the sample standard deviation, you would:

  1. Click on an empty cell (e.g., B1).
  2. Type =STDEV.S(A1:A10) and press Enter.
  3. The standard deviation of the data in cells A1 to A10 will be displayed in cell B1.

This method works for both small and large data sets, and Excel handles all the necessary calculations behind the scenes