Final answer:
The monthly payment that will repay the loan in 7.5 years is approximately $434.67. Karen will pay approximately $44,240.60 in interest over the life of the loan.
Step-by-step explanation:
In order to find the monthly payment that will repay the loan in 7.5 years, we can use the formula for monthly loan payments:

Where:
PMT = monthly payment
P = loan principal amount
r = interest rate per compounding period
n = number of compounding periods
Plugging in the given values:
P = $34,000
r = 0.033/2 = 0.0165 (semiannual interest rate)
n = 7.5 * 2 = 15 (number of compounding periods)
Solving the equation, we find that the monthly payment is approximately $434.67.
To calculate the total interest paid over the life of the loan, we can use the formula for compound interest:
Interest = Total Amount Paid - Loan Principal Amount
Plugging in the given values:
Total Amount Paid = Monthly Payment * Number of Payments
Total Amount Paid = $434.67 * 15 * 12 = $78,240.60
Interest = $78,240.60 - $34,000 = $44,240.60