Make a scatter plot to determine the relationship between the data. Then, find the equation of the line of best fit for the given data.
about 118.5 million dollars
Practice makes perfect
The given table shows the revenue in millions of dollars for a company over an eight-year period. We want to determine how much revenue the company will make in year 9 if the trend continues.
Year, x
1
2
3
4
5
6
7
8
Revenue (millions of dollars), y
20
35
46
56
68
82
92
108
Let's start by making a scatter plot showing our data. This will let us determine the relationship between the data.
The points appear to lie close to a straight line, which suggests that there is a linear relationship between the data. Let's use a graphing calculator to help us find the equation of a line of best fit to help us find the information we want. First, we enter the values into lists. Push STAT, choose Edit, and then enter the given values in the first two columns.
Next, to display an equation of the line of best fit, we press STAT, scroll to right to view the CALC options, and then choose the fourth option in the list, LinReg.
Now we can write an equation of the best fit for our data. Let's round the coefficient and constant to one decimal place for simplicity.
y=12.2x+8.7
We can use this equation to estimate the revenue in year 9 if we substitute 9 for x in our equation and simplify to find the value of y. Let's do it!
