Hi Guys,

Thank you in advance. Could anyone explain why my lecturers calculation for 99% confidence intervals

Does not equate to R's function:

```
t.test(study$Questions, conf.level = 0.99)
```

Which gives:

```
data: study$Questions
t = 78.112, df = 122, p-value < 2.2e-16
alternative hypothesis: true mean is not equal to 0
99 percent confidence interval:
47.36637 50.64989
sample estimates:
mean of x
49.00813
```

Any help on this matter greatly appreciated!