Box Plots and Outliers (the 1.5 × IQR Rule) | IB Maths AI SL Statistics

The seventh video in my IB Maths AI SL statistics series. How to draw a box plot from the five-number summary, how to decide if a value is an outlier using the 1.5 × IQR rule, and how to show an outlier on a box plot. We also do box plots on the TI-Nspire, look at what each part of a box plot tells you, check if the data is symmetric, and compare two box plots in context. There are pause questions and two exam-style questions. Have your GDC and notebook ready, and try them before you look at the answers. Lower fence = Q1 − 1.5 × IQR Upper fence = Q3 + 1.5 × IQR Previous video: Standard Deviation and Variance Next video: Histograms Chapters 0:00 Intro 0:40 Five numbers make a box plot 2:41 Step 1: put the data in order 3:29 Step 2: find Q1, Q3 and the IQR 4:21 Step 3: draw it on a scale 5:10 Outliers: the 1.5 × IQR rule 7:32 Is 15 an outlier? 8:30 Showing an outlier on a box plot 9:43 Box plots on the TI-Nspire 11:42 Each part holds 25% of the data 13:51 Is the data symmetric? 16:33 Comparing two box plots: did the diet work? 19:56 Exam-style question: the puzzle race 21:34 Exam-style question: screen time 22:14 Recap #IBMaths #IBMathsAI #Statistics