FP1 Linear Interpolation

Hi, I am self teaching FP1 and doing exercise 2B in the book for linear interpolation and for some reason my equation is different to the one in the solution bank, they put 2/9 instead of 9/2. I have followed the example in the book and believe I am setting up the equation correctly.

Could anyone shed some light as to why I am possibly wrong?

Thanks

Would this happen to be the thread? http://www.thestudentroom.co.uk/showthread.php?p=50842225&highlight=fp1%20linear%20interpolation

It seems the solution bank is incorrect then phew

no
the thread was a guy with a similar if not the same querry like you.
you can find it by searching in my profile my posts around 6 to 9 weeks ago

This is the thread that I think TeeEm is referring to:

http://www.thestudentroom.co.uk/showthread.php?p=51580423

Oh ok I see, thank you for your help guys, it seems the book is unreliable