Least Squares Regression Question

[BAH0003]

Hey guys,

I was working on this question and was having a bit of trouble getting to an answer. Is it okay if someone can explain this question and what the answer would be (it is B apparently)?

Thanks

[RuiAce]

It's actually just simultaneous equations.
\[ \text{Because we're given some of the predicted values}\\ \text{on the actual regression line, we just sub them in.} \]
\[ \text{So if the regression line is }y=a+bx\text{, we have}\\ \begin{align*} 10.7 &= a+900b\tag{1}\\ 6.7 &=a+1700b\tag{2} \end{align*} \]
\[\text{If you have calculators that solve simultaneous equations then just plug it in}\\ \text{but otherwise, }(2)-(1)\text{ gives}\\ 800b = -4 \implies \boxed{b = -0.005}\]
(Note of course that the slope is \(b\).)

[MEH0010]

Hey guys,

I was working on this question and was having a bit of trouble getting to an answer. Is it okay if someone can explain this question and what the answer would be (it is B apparently)?

Thanks

Hope this helps
*Answer is attached