Measuring active ingredient in medicine, σ = 0.0068
Firstly make the point that we are about 95% sure that the error from using any estimator will be less than 2SE. In the contest of estimating a popn mean, we are therefore 95% confident that µ is in the interval
The diagram shows a random sample (n = 16) and shows the calculations to find the 95% confidence interval.
Click Another sample and mention that the width of the interval is the same — it only depends on σ and n — but it is centred on the new sample mean.
Increase the sample size to show that the width of the CIs decrease.
Chemical analysis of pharmaceutical specimens is not precise. One analysis gives concentrations of an active ingredient that are centred on the true concentration, µ gm per litre.
X ~ normal (μ , σ = 0.0068)