Chapter 18, Problem 1SR

To determine

Determine the three-year moving average.

Plot both original data and the moving averages.

Answer to Problem 1SR

The three-year moving averages are 4, 5, 4 and 6.

The plot for original data and the moving averages is shown below:

Explanation of Solution

Calculation:

The three-year moving averages for sales are obtained below:

Year	Number Produced	3-year moving average
2011	2
2012	6	$\frac{2+6+4}{3}=4$
2013	4	$\frac{6+4+5}{3}=5$
2014	5	$\frac{4+5+3}{3}=4$
2015	3	$\frac{5+3+10}{3}=6$
2016	10

Step-by-step procedure to draw the scatter plot for data values and 3-year moving average values using the Excel:

• Enter the data for Year, Number Produced and 3-year moving averages in Excel sheet.
• Select the columns of ‘Number Produced’ and ‘3-year moving average’.
• Go to Insert Menu.
• Select Line chart.