Just tried calculating example 1, but the example uses units in hundreds, while the example answer seems to be using units in thousands. Am I missing something here?

When calculating with units in 100s I get y=32.857+0.068x, while using units in 1000s I get the same answer as the example answer.

Really sorry to be wasting your time if this is an error on my part.

I’ve noticed a couple of errors in the table being used here, so I can’t check my workings against this – the sum of Y is 409 not 420 and 54×54 is not 24225 as stated but 2916 and I can’t work out how the Sum of Y squared has ended up as 26550. Do you know where I could find other worked examples of this?

Hi, I am looking at the calculation of A and B in linear regression. You explained the formulas well, except what “n” stands for. Can you clarify please? Many thanks!

Hi, can I ask why you changed the units in the linear regression example from the notes please? For instance in the notes the units for January are 100 but you’ve used 1 in the lecture, so my answer for everything x related is out by a factor of 100 but my y answers are right, meaning my final answer is y=32.8+0.068x. Just not sure if I’m doing something wrong? Thank you!

bb1234 says

Just tried calculating example 1, but the example uses units in hundreds, while the example answer seems to be using units in thousands. Am I missing something here?

When calculating with units in 100s I get y=32.857+0.068x, while using units in 1000s I get the same answer as the example answer.

Really sorry to be wasting your time if this is an error on my part.

jenihen says

I’ve noticed a couple of errors in the table being used here, so I can’t check my workings against this – the sum of Y is 409 not 420 and 54×54 is not 24225 as stated but 2916 and I can’t work out how the Sum of Y squared has ended up as 26550.

Do you know where I could find other worked examples of this?

Ken Garrett says

I’m sorry about this. It’s been there for some years and you are the first to notice!

The same example is used in our notes and it is also wrong. I will correct it there and have new notes uploaded as soon as possible.

Thanks for reporting it.

marie02141 says

Hi,

I am looking at the calculation of A and B in linear regression. You explained the formulas well, except what “n” stands for.

Can you clarify please?

Many thanks!

Ken Garrett says

n is the number of pairs of readings.

Ken Garrett says

It simply keeps figures smaller when doing the workings. Things have to be converted back at the end, or realise x is in 00s.

Christine says

Hi, can I ask why you changed the units in the linear regression example from the notes please? For instance in the notes the units for January are 100 but you’ve used 1 in the lecture, so my answer for everything x related is out by a factor of 100 but my y answers are right, meaning my final answer is y=32.8+0.068x. Just not sure if I’m doing something wrong? Thank you!