In this question we have to use the formula of simple interest, which is
I = P r t
Where I is the interest earned, P is the amount invested, r is the rate of interest and t is the time duration .
In the given question, I = $4840 , r =11% or 0.11, t=11, P is unknown .
Substituting the values in the formula, we will get
[tex] 4840=0.11*11*P [/tex]
[tex] 4840=1.21 P [/tex]
P=4000
So she invested $4000.