Sum of series problem 23: why is my answer 14.4 instead of 2.84?

[jwxie]

Please look at the attachments (for the problem and my work) , thank you.

The answer from the book is 2.84 but I got 14.4.

How come?

My problem is #23

 

[mathman]

I didn't check all the details of your arithmetic, but it looks like you neglected to multiply by ∆x = .2.

 

[jwxie]

Thanks!