Before we can find the mean, median, mode, and range for the number of students who helped at the cookie booth each hour, we need to rearrange the numbers in the data set from least to greatest.

1, 3, 3, 4, 5, 8, 11

Now, let's find each value one at a time.

Mean

The mean of a data set is the average. We can calculate the mean by adding all the values and dividing by the number of observations.

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

SubstituteValues

Substitute values

Mean = \frac{1 + 3 + 3 + 4 + 5 + 8 + 1 1}{7}

AddTerms

Add terms

Mean = \frac{3 5}{7}

CalcQuot

Calculate quotient

Mean = 5

The mean number of students who helped at the booth is

5 .

Median

The median is the value found directly in the middle of a data set. Here we can see that the value in the middle is

4 .

1, 3, 3, 4, 5, 8, 11

The median number of students who helped at the booth is

4 .

Mode

The mode of a data set is the value or values that occur most often. In this case, it is

3 .

1, 3, 3, 4, 5, 8, 11

The mode of the number of students who helped at the booth is

3 .

Range

The range is the difference between the largest and smallest values. The largest number of students was

11

and the smallest number of students was

1 .

11 - 1 = 10

Therefore, the range of the number of students is

10 .

Exercise 1 Page p39

Hints

Check the answer

Mean

Median

Mode

Range