Find the average value on intercept

[tippeffect5]

Hi everyone.
I am stuck on this question for my final exam review.

Find the average value of : f(x)=2sinx+4cosx
on the interval [0,22π/6]


I keep getting an average value of 2.464 which is wrong.

Could anyone help me out please! Thanks!

 

[ksdhart]

Without seeing the work you did to get to your answer, we can't even begin to help you figure out where you might have went wrong. When you reply, please include a clear listing of all your steps and reasoning. Thank you.