1. Warm-Up Look at our planes dotplot What percent of people do you think flew their plane more than 30 feet? What percent of people do you think flew their plane less than 5 feet?

2. Describing Location in a Distribution Section 2.1

3. Measuring Position Percentile – the pth percentile of a distribution is the value with p percent of the observations less than it. Example – Alexis is in the 95 th percentile for height for her age…that means that 95% of three year olds are shorter than her. Payton is above the 99 th percentile for height…what does that tell us? What are some other examples where you have already seen percentiles in your daily life?

4. Example Use the scores of Mr. Pryor’s first statistics test to find the percentiles for the following students: Norman – earned a 72 Katie – earned a 93 The two students who earned 80’s Scores of class: 79 81 80 77 73 83 74 93 78 80 75 67 73 77 83 86 90 79 85 83 89 84 82 77 72

5. Cumulative Relative Frequency Graphs (these are also called “ogives”) These are made with percentiles! Example (President’s age at Inauguration): Age40-4445-4950-5455-5960-6465-69 Frequency27131273

6. Take that data and graph it!

7. Questions based on that… What percent of presidents were between 55 and 59? Was Barack Obama, who was inaugurated at age 47, unusually young? Estimate and interpret the 65 th percentile of the distribution.

8. Z-scores Standardized Value (z-score) – if x is an observation from a distribution that has a known mean and standard deviation, the standardized value of x is: “How many standard deviations above or below the mean”

9. Use Mr. Pryor’s tests… Mean is 80 Standard deviation is 6.07 Find the z-score for Katie – scored a 93 Find the z-score for Norman – earned a 72

10. Our planes answers! In order to find the actual percentiles (tomorrow) we need to find the z-scores of each observation I asked you about. 30 feet 5 feet

11. Computer Outputs

14. Transforming Data

15. Examples Look at our planes – What if I added three feet to every observation? What if we multiplied every observation by 2?

16. Homework Pg 105 (1-18)