Oscillations & Traveling Waves: How long is the string?

[aaa10196]

Homework Statement

A 111g ball is tied to a string. It is pulled to an angle of 4.40 Degrees and released to swing as a pendulum. A student with a stopwatch finds that 17 oscillations take 19.0s.
How long is the string?

Homework Equations

T = 2π√(L/g)

The Attempt at a Solution

Period T = 19/17 = 1.118s

g = 9.8m/s2

1.118/2π = √L/g
0.1779 = √L/g
0.0316 = L/g

L = 0.3101cm

This is wrong, someone please tell me my mistake.

 

[diazona]

Keep track of units, you'll find it.