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Jump to: Modes Entering Data Calculating the Mean, Standard Deviation, and Variance Entering Frequency Data Practice Opportunity 1 Practice Opportunity 2
Using Your Casio 300W Calculator - Single-Variable Statistics
With very little effort you can learn to use your calculator to calculate a number of important single-variable statistics.
Objectives
By the end of this learning activity, you will be able to:
Please make sure you have your calculator at hand.
The statistical functions of your calculator can save you from doing days and days of monotonous, repetitious busy work.
Press the [ON] button.
Press [MODE] once and you should see:
You calculator is always in one of these modes (Comp, SD, or Reg).
Since we are gathered here today, my brothers and sisters, to learn about the single variable statistical functions, please put your calculator in SD mode.
To select "SD" from the first menu, you press 2.
Press [ON]
Press [MODE]
Press [2]
You should see a very small SD near the middle bottom of the screen.
This section assumes your calculator is in SD mode. Before we begin, I want you to locate the data entry key [M+] on your calculator. It is the button just above the read [AC] button. It is also important that you do not confuse the negative button [(-)] on the left side of your calculator with the subtraction button which is on the lower right side of your calculator. The negative button [(-)], just above the [STO] button, is used to enter negative numbers. The subtraction button [–], just above the [=] button, is not used for data entry.
Let's imagine you want to find the mean, standard deviation, and variance of the following data:
12 |
Before you enter new data into your calculator, it is important that you clear the statistical memories.
Press [SHIFT] [AC] [=]
Your screen will show SCL for "Statistical Clear." Don't worry, this will disappear when we start entering data. Let's enter that data now:
Press [SHIFT] [AC] [=]
[1] [2] [M+]
[2] [3] [M+]
[(-)] [5] [M+] it is important that you press the negative button, not the subtraction button.
[
1] [4] [M+][
4] [M+]That's it!! Wasn't that easy? We only need to enter the data once, and as long as we do not clear our calculator, we can ask our calculator to compute a number of different statistics (or parameters) based on that data.
Calculating the Mean, Standard Deviation, and Variance:
To obtain the mean press:
[
SHIFT] [1] [=] Your display should read 9.6Before calculating the standard deviation and variance, you need to determine if your data constitutes the entire population or just a sample of a population.
If you have the data for the entire population:
To obtain the standard deviation, press [SHIFT] [2] [=]. Your display should read 9.478396489.
Once you have the standard deviation press [X2] [=] to get the variance. Your display should read 89.84.
If you have the data for only a sample:
To obtain the standard deviation, press [SHIFT] [3] [=] Your display should read 10.59716943.
Once you have the standard deviation press [X2] [=] to get the variance. Your display should read 112.3.
If your display did not show the numbers above, you probably pushed the red [AC] button when you should not have. When you press the red [AC] button, you clear out your data and need to re-enter all the data again before computing another answer based on that data. Moral to the story: Do not press the clear button unless you are entering a new data set.
1. What is the mean and variance of the following population.
24
74
21
-25
13
-35
Check answer by clicking here
Entering Data (Part 2) - Frequency Data
Value |
Frequency |
2 |
23 |
1 |
37 |
0 |
46 |
-1 |
102 |
-2 |
0 |
-3 |
1 |
The general form for entering frequency data is to enter the value then [SHIFT] [,] then the frequency then [M+]. The frequency is always positive. A value not followed by [SHIFT] [,] is treated as if the frequency is 1.
Before entering the data, make sure your calculator is in SD mode. Clear your statistical memories by pressing [SHIFT] [AC] [=].
Press [2] [SHIFT] [,] [2] [3] [M+]
Before pressing the [M+] your display will say 2;23, (the [SHIFT] [,] becomes a semicolon. When you press the [M+] your display will say 2 (the value). |
[ 1] |
[ SHIFT] [,] |
[ 3] [7] |
[ M+] |
[ 0] |
[ SHIFT] [,] |
[ 4] [6] |
[ M+] |
[ (-)] [1] | [ SHIFT] [,] | [ 1] [0] [2] | [ M+] |
[ (-)] [2] | [ SHIFT] [,] | [ 0] | [ M+] |
[ (-)] [3] |
[ SHIFT] [,] |
[ 1] |
[ M+] |
Value |
; |
Frequency |
Enter |
2. What is the variance and mean of the population from which the following data was sampled:
Value |
Frequency |
27 |
102 |
13 |
1 |
0 |
7 |
-12 |
13 |
24 |
0 |
-39 |
6 |
Check answer by clicking here.
That is it for the calculator until we get into bivariate statistics.