Confidence Intervals for One Mean: Sigma Not Known (t Method)

Introduction to confidence intervals for mu based on the t distribution. These methods are appropriate when we are sampling from a normally distributed population and the population standard deviation (sigma) is not known. The cereal data used in this video is real data from a sample of 7 cereal boxes I purchased one day. The boxes had a stated weight of 750 grams. (I've changed the story slightly in the video, but it is real data.) For those that use R, below is the R code to find the values given in the video. With 6 degrees of freedom, the t value with an area of 0.025 to the right (and thus an area of 0.975 to the left), can be found with: qt(.975,6) [1] 2.446912