Exercise 1 Page P27

The first thing that should be done when finding the key features of a data set is rearranging the numbers from least to greatest.

224, 272, 308, 374, 394, 404, 478, 480, 624, 960

Let's proceed to finding the mean, median, and mode.

Mean

The mean of a data set is calculated by finding the sum of all values in the set and then dividing by the number of values in the set. In this case, there are

10

values in the set.

Mean = \frac{Sum of values}{Number of values}

SubstituteValues

Substitute values

Mean = \frac{2 2 4 + 2 7 2 + 3 0 8 + 3 7 4 + 3 9 4 + 4 0 4 + 4 7 8 + 4 8 0 + 6 2 4 + 9 6 0}{1 0}

AddTerms

Add terms

Mean = \frac{4 5 1 8}{1 0}

CalcQuot

Calculate quotient

Mean = 451.8

Median

To identify the median, we observe the middle value.

224, 272, 308, 374, 394 ∣ 404, 478, 480, 624, 960

In this case there is no middle value. When this happens, we need to calculate the median by finding the average of the two central values. Once arranged from least to greatest, we find that

394

and

404

are the two central values.

Median = \frac{3 9 4 + 4 0 4}{2} = 399

Mode

The mode of a data set is the value that occurs most frequently.

224, 272, 308, 374, 394, 404, 478, 480, 624, 960

In this set, each number occurs only once. Therefore, there is no mode.