Find a line of best fit for the data

Question

Help. I used slope formula and line formula to write the equation but I am not getting the answer on the key!

the data says

X Y

$25.62 $4.50

$37.94 $6.50

$16.25 $3.25

$42.98 $7.50

$28.32 $5.00

are there multiple answer choices for this question? The key said the answer is Y=.16x + .55. How?!

Answer 1

You need to do linear regression on a TI-84 calculator to get the exact answer. Not all the time with data will it go through 2 points perfectly so you can calculate the slope and y intercept.

Go to STAT-EDIT

Put in your X values in for L1 and Y values in for L2

Go to STAT- CALC-#4 Lin Reg (ax+b)

Make sure it says L1, L2 since this is where your data is located.

It will be you the same values for a and b to make the solution you have.