## One Sample T Confidence Intervals

The R function `t.test`

(on-line
help) does `t` tests and confidence intervals.

does the example on the slides for class.

This example can also be done reading the data from a URL

## Two Sample T Confidence Intervals

The R function`t.test`

also does two-sample tests.
### Assuming Equality of Variances

does the example on the slides for class.

### Welch's Approximation

does the example on the slides for class.