# Measures of Central Tendency

## Presentation on theme: "Measures of Central Tendency"— Presentation transcript:

Measures of Central Tendency
Mean, Median and Mode Mean, Median, and Mode Measures of Central Tendency

Mean, Median and Mode What is the mean?
The SUM of the data, divided by the number of items in the set of data ….. commonly called “the average”.

The data item that appears the “MOST”
Mean, Median and Mode What is the mode? Mean, Median, and Mode The data item that appears the “MOST”

What if the data all appear the same number of times?
Mean, Median and Mode What if the data all appear the same number of times? 1,1,2,2,3,3,4,4 Mean, Median, and Mode

1,1,2,2,3,3,4,4 Mean, Median, and Mode There is NO mode

Can there be more than one mode?
1,2,2,3,4,4,5,6,7 Mean, Median, and Mode

1,2,2,3,4,4,5,6,7 Yes, there are two modes. What are they? 2 and 4
Mean, Median, and Mode 2 and 4

Mean, Median and Mode What is the median? Mean, Median, and Mode

Reorder from least to greatest
What is the median? The middle number in the set of data when written “in order” (first step we do) Given: 2,14,28,0,1,1 Reorder from least to greatest 0,1,1,14,28 The middle number is 1 Mean, Median, and Mode

What if you have an even set of numbers?
Given: 10, 0, 20, 30 Reorder from least to greatest 0,10, 20, 30 Add the two middle numbers together. Mean, Median, and Mode Divide by 2. What is your median? 15

Mean, Median and Mode What is an outlier?
Which will an outlier affect the most: the mean, median or mode? (Hint: Think of class test scores What is an outlier? Mean, Median, and Mode A data item that is far apart from the rest of the data items

The difference between the largest and smallest data values
Mean, Median and Mode What is the range? Mean, Median, and Mode The difference between the largest and smallest data values

Mean, Median and Mode Let’s try one …
Step 1 – Rewrite in order from least to greatest Mean, Median and Mode Let’s try one … Mean, Median, and Mode 2, 1, 0, 1, 5, 3, 4, 2, 0, 3, 1, 2

Mean, Median and Mode Mean Range 5 Median Mode 1 and 2 Mean, Median, and Mode 2, 1, 0, 1, 5, 3, 4, 2, 0, 3, 1, 2

Mean, Median and Mode Test scores in an Algebra class: 99, 85, 80, 25, 99, 100 What is the mean, median, mode and range? Mean, Median, and Mode Mean Median 92 Mode 99 Range 75

Mean, Median and Mode Write a paragraph about what would be your most useful indicator of central tendency in this case: You are ordering a small number of shoes for your shoe store based on the sales of sizes from last year. Write why you made your selection. Why did you not choose the other two? Mean, Median, and Mode