Calculating Electric Field Strength from a Charged Wire

[kmikias]

Homework Statement

The electric field strength 8.05 cm from a very long charged wire is 1310 N/C. What is the electric field strength (in N/C) 30.0 cm from the wire?

Homework Equations

E=F/Q
E=KQ/R^2

The Attempt at a Solution

First I try to find the charge using E=KQ/R^2
1320=K(Q)/(8.05)^2
Q= 9.432 x 10^-6

second I used the charge to find the electric field.
E= k(9.432 x 10^-6)/30^2
E= 94.32 N/C

I didn't convert cm to m because it would cancel out at the end.
so I don't know why my answer is still wrong.Any help will be great.
thanks guys.

 

[LonghornDude8]

You are assuming the wire is a point charge, which it is not. You would have to integrate:
2 (Integral from 0 to infinity) kdq/r^2
I hope you know what to do from there