11.a Mean Median Mode

11.a Mean Median Mode

Mean - Average of all numbers

• Add all of the numbers

• Then divide by total amount of numbers

What is the mean of

9, 9, 10 , 8, 5

• 9+9+10+8+5 = 41

• there are 5 numbers

• 41 divided 5 = 8.2

What is the mean of

42, 36, 47, 49, 50, 37, 40, 25

• 42+36+47+49+50+37+40+25 = 326

• there are 8 numbers

• 326/8 = 40.75

Mode - the middle number

1. Must be in lowest to highest order.

2. If there is an even number, then average the two middle numbers.

Find the median.

1,2,3,4,5,6,7

• its already in order

• 4 is the middle number so 4 is the median

• easier one

Find the median

2,4,6,8,10,12

• Its in order

• 6 and 8 are the middle two numbers

• the average of 6 and 8 is (6+8)/2 = 7

• 7 is the median

Find the median

5, 8, 9, 4, 3, 3 , 2, 7, 1

• put in order 1, 2, 3, 3, 4, 5, 8 ,9

• 3 and 4 middle two numbers

• (3+4)/2 = 3.5

• Median is 3.5

Mode - which number shows up the most

• Does not have to be in order, but it does help.

• Can have multiple numbers.

What is the mode?

1 2 2 2 3 3 4 5 6 6 7 7 7 7

• 7 happens the most.

• Mode is 7

What is the mode?

5 7 8 6 4 5 9 8 7 1 4 2 3 5 8

• 5 happens 3 times

• 8 happens 3 times

• Mode is 5 and 8