Statistics Examples

5

$5$ ,

3

$3$ ,

13

$13$ ,

1

$1$ ,

10

$10$ ,

n = 3

$n = 3$

Step 1

Find the data range by subtracting the minimum data value from the maximum data value. In this case, the data range is

13 - 1 = 12

$13 - 1 = 12$ .

12

$12$

Step 2

Find the class width by dividing the data range by the desired number of groups. In this case,

\frac{12}{3} = 4

$\frac{12}{3} = 4$ .

4

$4$

Step 3

Add one to

4

$4$ to get the size of each group.

5

$5$

Step 4

Start with

1

$1$ and create

3

$3$ groups of size

5

$5$ .

\begin{array}{c} Class & Class Boundaries & Frequency \\ 1 - 5 \\ 6 - 10 \\ 11 - 15 \end{array}

$\begin{array}{c} Class & Class Boundaries & Frequency \\ 1 - 5 \\ 6 - 10 \\ 11 - 15 \end{array}$

Step 5

Determine the class boundaries by subtracting

0.5

$0.5$ from the lower class limit and by adding

0.5

$0.5$ to the upper class limit.

\begin{array}{c} Class & Class Boundaries & Frequency \\ 1 - 5 & 0.5 - 5.5 \\ 6 - 10 & 5.5 - 10.5 \\ 11 - 15 & 10.5 - 15.5 \end{array}

$\begin{array}{c} Class & Class Boundaries & Frequency \\ 1 - 5 & 0.5 - 5.5 \\ 6 - 10 & 5.5 - 10.5 \\ 11 - 15 & 10.5 - 15.5 \end{array}$

Step 6

Draw a tally mark next to each class for each value that is contained within that class.

\begin{array}{c} Class & Class Boundaries & Frequency \\ 1 - 5 & 0.5 - 5.5 & | | | \\ 6 - 10 & 5.5 - 10.5 & | \\ 11 - 15 & 10.5 - 15.5 & | \end{array}

$\begin{array}{c} Class & Class Boundaries & Frequency \\ 1 - 5 & 0.5 - 5.5 & | | | \\ 6 - 10 & 5.5 - 10.5 & | \\ 11 - 15 & 10.5 - 15.5 & | \end{array}$

Step 7

Count the tally marks to determine the frequency of each class.

\begin{array}{c} Class & Class Boundaries & Frequency \\ 1 - 5 & 0.5 - 5.5 & 3 \\ 6 - 10 & 5.5 - 10.5 & 1 \\ 11 - 15 & 10.5 - 15.5 & 1 \end{array}

$\begin{array}{c} Class & Class Boundaries & Frequency \\ 1 - 5 & 0.5 - 5.5 & 3 \\ 6 - 10 & 5.5 - 10.5 & 1 \\ 11 - 15 & 10.5 - 15.5 & 1 \end{array}$