Answer:
Balance of savings account at the end of 3rd month = $753.13
Step-by-step explanation:
Balance at the end of 1st month :
Principal = $250 , Time = 1 month , n = 12 , APR = 2.5%

Balance at the end of second month :
Principal = 250 + 250.52
= 500.52
Time = 1 month, APR = 2.5%, n = 12

Balance at the end of third month :
Principal = 250 + 501.56
= 751.56
Time = 1 month, APR = 2.5%, n = 12

Hence, Balance of savings account at the end of 3rd month = $753.13