1. Chapter 1 Unit Question How do numbers measures, graphical representations and expressions represent mathematical situations?

2. Open Learning Logs Date on Left…Section 1 – 6 on right

3. Make a list of everything you can remember about statistics from last year 1 – 6 Warm – Up

4. Section 6 How do we calculate and use the measures of central tendency?

5. Homework Check

6. Measure of Central Tendency: A value to illustrate where data are centered Mean: Average of the data (add ‘em up and divide!) Used when there are NO outliers Median: Middle number of a set of data when the numbers are in order Used when outliers exist Mode: The piece of data that appears the most Outlier: A piece of data way outside the other values of data Definitions…

7. Find the Mean, Median and Mode… The wages of employees at a local restaurant are shown $6.25 $6.50 $6.75 $7.00 $7.25 $7.50 $7.75 $8.00 $8.25 X XX X X X X X X X Mean: Median: 6.25 6.25 6.25 6.25 6.25 6.50 6.50 6.50 7.00 8.25 Mode: 6.25 Which is the best measure of central tendency and WHY? Median: Mode:

8. SOLVE!!! Suppose your grades on three history exams are 80%, 93%, and 91%. What grade do you need on your next exam to have a 90% average on the four exams? Let x = the fourth exam score You would need a 96% on the last exam to average 90%.

9. Definitions: Stem and Leaf Plot: graph that uses PLACE VALUE for data Range: the difference between the greatest and least values Range = Max – Min READY?

10. Let’s do it… The city and highway mileage for 9 new cars are listed… CITY 19, 31, 34, 20, 29, 31, 28, 23, 23 HIGHWAY 41, 30, 27, 38 38, 28, 32, 37, 32 12341234 9 0 3 3 8 9 1 1 4 12341234 7 8 0 2 2 7 8 8 1 Sometimes a “back-to-back” stem and leaf is useful… Next slide please

11. CITY 19, 31, 34, 20, 29, 31, 28, 23, 23 HIGHWAY 41, 30, 27, 38 38, 28, 32, 37, 32 12341234 9 0 3 3 8 9 1 1 4 12341234 7 8 0 2 2 7 8 8 1 12341234 7 8 0 2 2 7 8 8 1 9 9 8 3 3 0 4 1 1 What is the range of City mileage? 32 AND 38 What is the median of Highway mileage? What is/are the mode(s) of highway mileage?

12. Homework Do HoffmaSheet 1 – 6