To make a confidence interval for the difference

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: nt) Means Note: These procedures will ask if you want to use the pooled standard deviation procedures—these are rarely used, so use them only if your instructor tells you to. To make a confidence interval for the difference between two population means: 1. Press K and scroll to the TESTS menu. 2. Scroll down until you find the option 2–SampTInt and select it. 3. If you have the data, select the Data option, and enter the list names with the data. See the top screen to the right. 4. If you have only the summary statistics, choose the Stats option and enter the summary statistics (sample mean and standard deviation, and sample size) for each of your samples. See the second screen to the right. 5. Determine your confidence level. 6. If you are using the pooled procedures, select Yes; otherwise, select No. You may have to scroll down to see this line. 7. Scroll down and select Calculate. Press [. Displayed is the interval for the difference m1 - m2. Other details of the calculation are also displayed: the degrees of freedom and all the summary statistics. You need to scroll down to see them all. To conduct a hypothesis test: 1. Write down your null and alternative hypotheses. 2. Press K and scroll to the TESTS menu. 3. Scroll down until you find the option 2–SampTTest and select it. 4. If you have the data, select the Data option and enter the list names with the data. This is shown in the screen to the right. 5 7. 8. Inference for Two Sample (Paired) Means The following instructions assume that one set of data is in L1 and the other in L2 and that the paired difference we will compute is L2– L1. Alternatively, you can calculate the differences by hand and store the differences directly in a list, say L3. To have the calculator compute the paired differences, L2 –L1: 1. Press K, select the Edit menu, and input your data into lists L1 and L 2. 2. Clear L3 by moving the cursor up to highlight L3 and pressing P. 3. Move the cursor back to highlight L3. 4. Type in the formula L2 – L1 by pressing this sequence of keys: F 2 c F 1. See the screen to the right. 5. Press [. You should now see the calculated differences stored in L3. To find a confidence interval or conduct a hypothesis test on the paired mean difference, follow the instructions under Confidence Intervals and Hypothesis Tests for a Mean using the differences stored in L3. Chi Squared Goodness-of-Fit Test Note: Several versions of the TI-83/84 calculator have this test built-in. If yours does not, skip the first set of instructions and move on to the second. These instructions assume that you have the list of observed counts in L1 and the list of expected counts (generated from the probabilities in your null hypothesis) in L2. To perform a test with the built-in function: 1. Press K and scroll to the TESTS menu. 2. Scroll down until you find the option X 2 GOF–Test and select it. If you don’t see this, move to the next set of procedures. 3. Enter the list names with your observed and exp...
View Full Document

Ask a homework question - tutors are online