Question

Using the hottest and coolest months data, find the equation for line of best fit for this data showing all steps by hand.

Answer 1

Let

x -----> average temperature

y ----> Electricity Bill

we take the points

(99,150) and (69,80)

step 1

Find out the slope

m=(80-150)/(69-99)

m=-70/-30

m=7/3

step 2

Find out the equation of the line in slope-intercept form

y=mx+b

we have

m=7/3

point (69,80)

substitute and solve for b

80=(7/3)(69)+b

b=80-161

b=-81

the equation is

y=(7/3)x-81

using a graphing tool

Remember that the value of y cannot be a negative number