Trevor invested $ 4720
<em><u>Solution:</u></em>
Given that, Trevor earned $ 826 on account during 2.5% annual interest for seven years
We can simple interest formula
<em><u>The formula for simple interest is given as:</u></em>
Where,
"p" is the principal
"n" is the number of years
"r" is the rate of interest
Here given that,
Principal = p = ?
rate of interest = r = 2.5 %
number of years = n = 7
Simple interest earned = 826
<em><u>Substituting the values in above formula,</u></em>
Thus he invested $ 4720