The steps for constructing a confidence interval or conducting a paired means \(t\) in Minitab are identical. The output that the procedure provides includes both the confidence interval and the \(p\)-value for determining statistical significance.
Minitab® – Conducting a Paired Means Test
Let's compare students' SAT-Math scores to their SAT-Verbal scores.
- Open the Minitab file: class_survey.mpx
- Select Stat > Basic Statistics > Paired t
- Select Each sample is in a column since we have the data in the worksheet
- Double click the variable SATM in the box on the left to insert the variable into the Sample 1 box
- Double click the variable SATV in the box on the left to insert the variable into the Sample 2 box
- Click OK
This should result in the following output:
Paired t: SATM, SATV
Sample | N | Mean | StDev | SE Mean |
---|---|---|---|---|
SATM | 215 | 599.81 | 84.70 | 5.78 |
SATV | 215 | 580.33 | 82.44 | 5.62 |
Mean | StDev | SE Mean | 95% CI for \(\mu_d\) |
---|---|---|---|
19.49 | 89.81 | 6.12 | (7.42, 31.56) |
\(\mu\)_difference: population mean of (SATM - SATV)
Null hypothesis | H0: \(\mu\)_difference = 0 |
---|---|
Alternative hypothesis | H1: \(\mu\)_difference ≠ 0 |
T-Value | P-Value |
---|---|
3.18 | 0.002 |
On the next page, the five-step hypothesis testing procedure is used to interpret this output.