Final answer:
The average interest gained from the three accounts in one year is calculated by first determining the individual interest for each account and then finding the mean of these interests, resulting in an average of $882.89.
Step-by-step explanation:
To find the average interest gained from the three accounts in one year, we first calculate the interest for each account separately and then find the average of those amounts.
- Interest for Bank A = $250.67 × 12% = $30.08.
- Interest for Bank B = $765.13 × 7% = $53.56.
- Interest for Bank C = $28,500.36 × 9% = $2,565.03.
To find the average, we add the three amounts of interest and divide by 3:
Average Interest = ($30.08 + $53.56 + $2,565.03) / 3 = $2,648.67 / 3 = $882.89.
Therefore, the average interest gained from the three accounts in one year is $882.89.