Instruction on calculating Standard Deviation in Excel

Standard Deviation Formula

1. Copy the data to excel

2. Calculate the mean a)Select a cell in excel b)Enter the = sign in the cell c)Type in Average d)Double click on the formula and select the data e)Close parenthesis by doing Shift + 0 f)Press Enter

3. Find the Dispersion a)Dispersion is the difference between each data and the mean. b)Next to the column near the first data c)Enter the equal sign d)Select the first data e)Enter the minus sign f)Select the mean g)Enter

3. Continue a)Next we want to copy the dispersion formula for the rest of the data. To do this we need to make the mean cell fixed i.For that select the cell ii.Click next to the cell number which in this example is A11 iii.Function + F4, note this will place $ next to cell column and row the. i.e. $A$11 b)Now place your mouse in the lower right corner of the cell, once you see the filled in plus sign, left click and drag down

4. Dispersion squared a)Go to the next column on the first row b)Enter the equal sign c)Select the Dispersion cell, in this example B4 d)Then Shift + 6 e)The number 2 f)And then enter

4. Continue a)Now we need the same formula for all the other values. So place your mouse in the lower right corner of the cell, once you see the filled in plus sign, left click and drag down

5. Sum the dispersion squares a)Select a cell b)Enter the equal sign c)Enter the word sum d)Select the data e)Shift + 0 to close the parenthesis f)Enter

6. Divide the number from step 5 a)If you are calculating the sample standard deviation divide the number from step 5 by one less than the number of data. If you are calculating the population, then divide the number from step 5 to number of data b)Select a cell c)Enter the equal sign d)Select the cell that has step 5’s value e)The division sign f)Then enter the number. For this example there are 7 numbers. So we divide by 7 g)Enter

7. Take square root a)This is the last step. We need to take the square root of the number we found in part 6. To do that follow the following steps b)Enter the equal sign into a cell c)Then type SQRT and select Excel's formula d)Select the cell from step 6 e)Shift+0 to close parenthesis f)Enter

All together Here is the entire excel parts: