Linear equations

Question

This is a table data which is in years and families below poverty level (in thousands)

2000-6400

2001-6813

2002-7229

2003-7607

2004-7623

2005-7657

2006-7668

2007-7835

2008-8147

first question says

a) Find a linear equation for the number of families living below the poverty level (in thousands) in terms of x, the number of years since 2000, using the data for 2000 and 2008

Note: i resolve First question and the answer I got is y=218.375x+6400 but I don’t know how to answer the rest of the questions

second question says

b) Repeat part a) using the data for 2004 and 2008

third question says

c) Find the equation of the least squares line using all the data. Then plot the data and the three lines from part a)-c).

Answer 1

Your work for part A is correct.

For part b you will find the slope of the equation using the new points (4, 7623) and (8, 8147). Then use the slope and one of the two points in point slope form y-y₁=m(x-x₁) where m is slope and (x₁,y₁) is the point you chose. Ex. y-7623=131(x-4) using the 2004 point.

Part C can be solved with a graphing calculator doing a linear regression. Using demos.com, enter the data into a table and enter the equation y₁~ mx₁+b in the second box. The calculator with give you values for m and b. You can also use demos to see all three equations graphed with the data values.