Question 1: Using SPSS, calculate a 95% confidence interval for mean FEV1.
To do this we choose Analyze, Descriptive Statistics, Explore, variable FEV1, OK.
We get the following output:
| Descriptives | ||||
|---|---|---|---|---|
| Statistic | Std. Error | |||
| FEV1 (litre) | Mean | 4.0607 | .08895 | |
| 95% Confidence Interval for Mean | Lower Bound | 3.8825 | ||
| Upper Bound | 4.2389 | |||
| 5% Trimmed Mean | 4.0561 | |||
| Median | 4.1000 | |||
| Variance | .451 | |||
| Std. Deviation | .67153 | |||
| Minimum | 2.85 | |||
| Maximum | 5.43 | |||
| Range | 2.58 | |||
| Interquartile Range | .99 | |||
| Skewness | .064 | .316 | ||
| Kurtosis | -.857 | .623 | ||
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Last updated: 6 October, 2006.