Unformatted text preview: ected counts and the degrees of freedom for the test (the number of categories –1).
4. Select Calculate and press [. The results display the test statistic, x2, and the p-value, p, along with some other information.
To perform the test step by step:
1. After entering the observed and expected counts into L1 and L2, respectively, move the cursor to
highlight the list name L3. Clear this list and return the cursor to highlight the name L3.
2. With L3 highlighted, type the formula for the test statistic using the following keystrokes:
The result is shown in the screen to the right. Press [. L3 should ﬁll with the calculated values.
3. Press F G to QUIT the list edit screen.
4. Press F K to enter the LIST menu, and scroll to the MATH menu. Select option 5:sum(.
5. Type in L3 as shown in the screen to the right. Press [. This is your chi-squared test statistic.
6. Press F O to get to the DISTR menu, and select X 2 cdf(. Type in the value of the test statistic computed in step 5 (or use the ANS feature), enter a large number such as 99999, and enter the
degrees of freedom for the test, all separated by commas. Press [. This is your p-value. 6 TI_card_570774_reprint.qxp 2/12/09 3:43 PM Page 2 TI–83/84®
Inferences for Proportions (continued) Conﬁdence Intervals and Hypothesis Tests for a Mean Inference for Two Sample (Independent) Means (continued) To do a hypothesis tests for a proportion:
1. Write down your null and alternative hypotheses.
2. Press K and scroll to the TESTS menu.
3. Scroll down to 1–PropZTest and press [.
4. Look at your null hypothesis and type in the proportion stated there in the slot next to the p0.
5. Enter the number of successes (x) and sample size (n) for your sample.
(Again number, not proportion, of successes.)
6. Look at your alternative hypothesis. In the row beginning with the prop, use the arrow keys to move
the cursor left or right to select the correct form of your alternative hypothesis. Press [ to select
it. In the screen above, the two-tailed (not equal) option is selected.
7. Move the cursor over the word Calculate and press [. The output screen repeats the form of the
alternative hypothesis selected. The test statistic, or z-score, z, and the p-value, p, are given. The
results also report the sample proportion and sample size.
You can also select the option Draw in the 1–PropZTest. This will display visually the results of the test
as in the screenshot to the right. The screen reports the test statistic (the z) and the p-value (the p).
WARNING: It is possible you will get an error message that reads ERR: DOMAIN or, when using the Draw option, ERR: SYNTAX
If you do, try the following:
1. Check that your input for x is an integer. Redo the test and make sure that x is truly a whole number, not a decimal.
2. You may have several plots that the calculator is trying to plot at the same time that are incompatible. Press the E key and
clear any extraneous equations or keystrokes by scrolling down and pressing P. If you have more than one stat plot on, yo...
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