This activity is about calculating the mean, median and range of a dataset.

 

Remember

To find the mean, add up all the values and divide by the total number of values.

 

The median is the middle value, once the numbers have been put in order (lowest number to highest number). If there are two middle numbers, find the mean of these two middle numbers.

 

The range is the difference between the largest and smallest values.

 

 

Example

Calculate the mean, median and range of this dataset.

 

Minimum temperatures in ^oC over 1 week:

 

7, 3.5, 2.5, -1, -4.5, 5, -2

 

Answer

First, find the total which is 7 + 3.5 + 2.5 - 1 - 4.5 + 5 - 2 = 10.5

Mean = total ÷ number = 10.5 ÷ 7 = 1.5 ^oC

 

For the median, place them in increasing order.

-4.5, -2, -1, 2.5, 3.5, 5, 7

The middle number is the 4th number in the list.

Median is 2.5 ^oC

 

Range = largest value - smallest value = 7 - -4.5 = 7 + 4.5 = 11 ^oC

 

Did you remember that two negatives make a positive? 7 - -4.5 = 7 + 4.5 = 11

 

On to the questions now!