6.15

Mean Median Mode

Click the happy face to see a power point

by Jennifer Del-Castillo of JFKM

Control/Click the link to play a practice game

http://www.kidsmathgamesonline.com/numbers/meanmedianmode.html

1. Find the mean for a set of data.

2. Describe the three measures of center and a situation in which each would best represent a set of data.

3. Identify and draw a number line that demonstrates the concept of mean as balance point for a set of data.

This is the stuff you will need to be able to do

Easy!!

NOT QUITE AS EASY

DIFFERENT, BUT NOT SO HARD

Get ready to set up your Interactive Notebook

6.15a) describe mean as a balance point b) decide which measure of center is

appropriate for a given purpose

Make a cover sheet

Mean Median Mode

Write the following terms in your notebook with the heading

6.15 Vocabulary

Mean

Mean –The sum of the numbers in a set of data divided by the number of pieces of data.

EX- grades averaged: 2, 6, 7, 7, 10Add them up= 32Divide by how many numbers are in the data set 32/5 = 6.4

Synonyms are Fair Share, Average, Balance Point

The number(s) or item(s) that appear mostoften in a set of data.EX- 85, 92, 100, 100, 91, 86, 78 The Mode is 100.

If there are exactly two modes the data set is

bimodal.

Mode

The middle number in a set of data when arranged in numerical order. Think of the median of the road, right in the middle..EX Odd Set- 85, 72, 100arrange 72, 85, 100 The median is 85.

Ex Even Set- 85, 92, 100, 105The median is the average of 92 and 100. 92 + 100= 192 divide by 2 and the Median is 96.

Median

Information, often numerical, which is gathered for statistical purposes. EX- Grades for a 9 weeks

DATA

The difference between the greatest number and the least number in a set of data.EX- 2, 9, 6, 8 Place in numerical order 2,6,8, 9Subtract smallest number from greatest number 9-2Range = 7

Range

A number that helps describe all of the data in a data set.Ex- Mean, Mode, Median, Range

Measures of Central Tendency

Outlier-

A number that is numerically distant from the rest of the data

If students scored a 100, 89, 92, 79, and 23,23 is Way Off from the other scores. 23 is the outlier.

Which Measure of Central Tendency?Mean works well for sets of data with no very high or low numbers.

Median is a good when data sets have a couple of values much higher or lower than most of the others.

Mode is a good to use when the data has some identical values or when working with data in a yes or no survey.

Okay, give your hand a break and read the next few slides

Mean can be defined as the point on a number line where the data distribution is balanced.

This is the concept of mean as the balance point.

This seesaw is NOT balanced!

For example, to balance, a seesaw would need the same weight or value on each side

Now think of a number line as a line plot. The fulcrum (triangle) is the mean.Here the mean is 12. We have been given three plotted points. But to balance, we need to have two points on each side of the line plot!So how do you figure that out!

First, draw a line up through 12Next, count how far apart the plotted numbers are from 12 on each side. Plot corresponding circles on each side to balance!

33 55

THE NUMBERS 7,9, 15,AND 17 HAVE A MEAN OF 12!

Now you try!

What is the missing point?

Now you try!

What is the missing point?6 !!!

Here is another way you willbe asked to answer for

the balance point, or mean.

There will be counters on a number line. Each counters represents a unit of the number it is sitting at. 1 x 4= 4 2 x 6 = 12 and so on.

What you will be asked to do is jump the counters to find the mean. You start at the outside edges. Click to see.

THE BALANCE POINT,

OR MEAN, IS 7

Do you think you are ready to try on your own!

Before we start make sure you have

this in your notebook….

The points must balance on both sides of the balance point (mean)

Move the outside counters from each side towards the center to meet the balance point