Section 2.2, Part 2 Determining Normality AP Statistics
AP Statistics, Section 2.2, Part 22 What is “Normal”? Because we should only apply z-score to distributions that are normal, we need a process to determine whether a distribution is a normal distribution.
AP Statistics, Section 2.2, Part 23 Symmetric? The distribution should be roughly symmetric. You can use a Boxplot to determine symmetry.
AP Statistics, Section 2.2, Part 24 Are Walter Johnson’s Wins Normal? 5, 14, 13, 25, 25, 33, 36, 28, 27, 25, 23, 23, 20, 8, 17, 15, 17, 23, 20, 15, 5 into list L 1 Run “1-Var Stats” Is the data set symmetric? Where do you look?
AP Statistics, Section 2.2, Part 25 Are Walter Johnson’s Wins Normal? Look also at boxplot Is the data set symmetric?
AP Statistics, Section 2.2, Part Rule? You can use the rule with a histogram to see if the distribution roughly fits the rule.
AP Statistics, Section 2.2, Part 27 Are Walter Johnson’s Wins Normal? 5, 5, 8, 13, 14, 15, 15, 17, 17, 20, 20, 23, 23, 23, 25, 25, 25, 27, 28, 33, 36
AP Statistics, Section 2.2, Part 28 Are Walter Johnson’s Wins Normal? Last step is the creation of the “normal probability plots Let’s look at the book example:
AP Statistics, Section 2.2, Part 29 Example 2.12 XMidpointY 11/8= /8= /8= /8=
AP Statistics, Section 2.2, Part 210 Example 2.12 XMidpointY 11/8= /8= /8= /8=
AP Statistics, Section 2.2, Part 211 Example 2.12 XMidpointY 11/8= /8= /8= /8=
AP Statistics, Section 2.2, Part 212 Somewhat normal (somewhat linear)
AP Statistics, Section 2.2, Part 213 Example 2.12 XMidpointY 11/10= /10= /10= /10= /10=
AP Statistics, Section 2.2, Part 214 Example 2.12 XMidpointY 11/10= /10= /10= /10= /10=
AP Statistics, Section 2.2, Part 215 Example 2.12 XMidpointY 11/10= /10= /10= /10= /10=
AP Statistics, Section 2.2, Part 216 Not normal (not linear)
AP Statistics, Section 2.2, Part 217 Walter Johnston Normal?
AP Statistics, Section 2.2, Part 218 Assignment Exercises 2.26 – 2.31, 2.33, 2.36 to finish Section 2.2 Exercises 2.39, 2.40, 2.42, 2.45, 2.47 to finish Chapter 2