Computing a confidence interval for $\mu_1-\mu_2$:

A. Computing ( 7.8) from two data lists:

1. [STAT]
2. [TESTS]
3. [2-SampTInt]. [ENTER].
4. Choose [DATA]. [ENTER].
5. Input the list names and the confidence level (must be a positive decimal).
Leave [Freq1] and [Freq2] at 1.
6. Choose [Pooled]: YES. [ENTER].
7. Arrow down to [Calculate]. [ENTER].

 

B. Computing ( 7.8) from $\overline{X}_1$, S₁, $\overline{X}_2$ and S₂

Follow Procedure C, but choose [STATS] in Step 4.

C. Computing the Paired-t confidence interval from two data lists

1. Suppose your data is in lists [L1] and [L2]. Take the differences and store in [L3] as follows: [STAT] [EDIT], scroll to header of [L3], [2nd][L1] - [2nd][L2] [ENTER]. 2. Follow Section  7.10.1 using data in [L3].