Question

Suppose you are given the following (x, y) data pairs. x 1 3 6 y 4 3 8 Find the least-squares equation for these data (rounded to three digits after the decimal). ŷ = Incorrect: Your answer is incorrect. + Incorrect: Your answer is incorrect. x (b) Now suppose you are given these (x, y) data pairs. x 4 3 8 y 1 3 6 Find the least-squares equation for these data (rounded to three digits after the decimal). ŷ = + x

Answer 1

we will solve using excel function SLOPE and INTERCEPT to find the corresponding equation

(A)  x 1 3 6 and y 4 3 8

using excel

=SLOPE(known y's, known x's)

= SLOPE(4,3,8;1,3,6)

= 0.868

And

=INTERCEPT(known y's, known x's)

= INTERCEPT(4,3,8;1,3,6)

= 2.105

So, y = 2.105 + 0.868*x

(B)  x 4 3 8 and y 1 3 6

using excel

=SLOPE(known y's, known x's)

= SLOPE(1,3,6;4,3,8)

= 0.786

And

=INTERCEPT(known y's, known x's)

= INTERCEPT(1,3,6;4,3,8)

= -0.595

So, y = -0.595 + 0.786*x