Question 3: What does ‘The 95% confidence interval is 0.4 to 6.0 units/week’ mean and what conclusion could we draw from it?
We are using the respondents as a sample of a larger population and estimating the difference in alcohol consumption between men and women in that larger population.
A confidence interval is a range of values which we estimate will include the difference in the population. A 95% confidence interval is chosen so that 95% of such samples would include the population value.
We can conclude that we estimate that, in the population which this sample represents, men report that they consume an average of between 0.4 and 6.0 more units of alcohol per week than do women.
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