**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 **
**, ***S*_{1}**, **
** and ***S*_{2}

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].