6.04 Curve of Best Fit

Try It

Determine the Line of Best Fit

Problem #1

The table shows the number if farms operating in the United States from 1998 through 2006.

Operating Farms in U.S.

Year (since 1998)	Number of Farms (in thousands)
0	2192
1	2187
2	2167
3	2149
4	2135
5	2127
6	2113
7	2009
8	1089

Use Geogebra's spreadsheet to find the line of best fit.

Step 1: In the spreadsheet enter the Years in column A and the Number of Farms in column B.

Step 2: Highlight the range of cells from A1:B9.

Step 3: Click on the bar chart and choose Two Variable Regression Analysis.

Step 4: Below Regression Model, click on the down arrow and choose Linear.

Step 5: You should now have an equation of the form y = mx + b below the Regression Model.

y = ?

Answer: y = -17.9333x + 2201.5111

Problem #2

Mary decides to run a 5K road race every Saturday morning for the next two months. The table shows the number of miles she runs per week, along with her weekly 5K results.

Miles Run Per Week

Miles Run (per week)	5K Time (min)
10	42
12.5	40
15	36
17.5	31
20	30
22.5	27
25	26

Use Geogebra's spreadsheet to find the line of best fit.

y = ?

Answer: y = -1.1429x + 53.1429

Problem #3

The table shows the average daily temperature of a small town in Alabama since January 1^st.

Average Daily Temperatures

Days	Temperature (°F)
0	62
2	60
4	67
6	63
8	81

Use Geogebra's spreadsheet to find the line of best fit.

y = ?

Answer: y = 2.05x + 58.4