Whats a confidence interval?
Look at your notes from Section 7.4.2 of the first half of the course. If you do n experiments to measure a quantity x, and your n measurements are X1, X2, …, Xn, then the procedure is as follows: • calculate the mean, μ=(X1 + X2 + … + Xn)/n. • calculate the variance, (Σ(Xi-μ)2)/(n-1) • calculate the standard deviation, σ=(variance)1/2 • the 95% confidence interval for x is then [μ-1.96σ μ+1.96σ].
