n - Middlesex Community College

Mean and Standard Deviation of a Frequency Distribution on the TI-83/84 Calculators
1) First, add up all the number of frequencies that occur within this distribution, this is your
n:
n = ________
2) Assign your x values to List 1 in your calculator, and your class midpoint values to List 2
These can be found under [STAT] → Edit.
3) Go to the title of List 3, and type: L1 * L2.
4) Press [STAT] → Calc → 1:1-VAR STATS .
5) Enter that you want the 1-VAR STATS for L3.
6) Take the line Σx and divide it by n is your μ; write it down
Σx₁ = _______
μ = ________
7) Go back to [STAT] → Edit
8) In the title of List 4, enter the following: L1²*L2
9) Once again, press [STAT] → Calc → 1:1-VAR STATS
10) Enter that you want the 1-VAR STATS for L4.
11) Write down the line Σx once more
Σx₂ = ________
12) Take Σx₂ and multiply it by n, take this result and subtract (Σx₁)²; divide this result by
[n(n-1)] and then take the square root.
13) This is your standard deviation:
σ = _________
Middlesex Community College | Prepared by: Stephen McDonald