Statistics

1. Statistics Mean, Median, Mode, and Range

2. Mode • Mode is the data item that appears most often. • Pizza, pizza, pizza, pizza, pizza, hamburger, hamburger, hamburger, taco, taco, taco, taco, spaghetti, spaghetti, spaghetti • Pizza would be the mode; it appears the most • For numbers it works the same way

3. Mode • 18, 19, 19, 20, 22, 23, 23, 23, 24, 34 • Find the mode of these numbers and then select the arrow key for an answer. • Mode = 23; this appears the most in this set of data.

4. Median • The median is the middle number in a set of data when it is in numerical order. • 4, 7, 9, 13, 25 • 9 is the middle number in this set. Start on each of the ends and work your way to the middle. If there is an odd number of numbers, the median is easy, it will be a number in your set. If there is an even number…..

5. Median • 18, 19, 19, 20, 20, 22, 23, 23, 24, 34 • Then you would take the two numbers in the middle and find their average. The numbers must be put in order numerically first! • 20 + 22= 44 42/2=21 • Now you try. What is the median of • 8, 42, 13, 7, 50, 91 • 7, 8, 13, 42, 50, 91 13+42=55 55/2=27.5

6. Range • The Range is the difference between the smallest and largest number. • 18, 19, 19, 20, 22, 23, 23, 23, 24, 34 • 34-18 = 16, so 16 is the range • Your turn! • 8, 7, 8, 9, 8, 7 • 9-7=2

7. Mean • The Mean of a set of data is the sum of all of the numbers in the data set divided by the total number of data items. • 2, 4, 5, 1 • 2+ 4+ 5+ 1 = 12 • 12/4 = 3

8. Mean • 3, 4, 7, 2, 5, 9 • 3 + 4 + 7 + 2 + 5 + 9 • 30/6 = 5

9. Practice • Find the mean, median, mode, and range for the following data sets. • 6, 4, 5, 9, 7, 6, 8, 3 • Mean: 6; Median: 6; Mode: 6; Range 6 b. 14, 16, 28, 17, 20 b. Mean: 19; Median: 17; Mode: No Mode; Range 14 c. 500, 450, 475, 450, 500 c. Mean: 457; Median 475; Mode: 450 and 500; Range: 50