Final answer:
Mrs. Dewhurst will not be charged a late fee because she made her car loan payment within the specified 30-day grace period, 15 days before its conclusion.
Step-by-step explanation:
Given that installment loans have a 30-day grace period and Mrs. Dewhurst makes her car loan payment 15 days into the grace period, she will not be charged a late fee. The grace period is a duration within which a borrower can make a payment without being subject to extra fees. Since she is within this timeframe, her payment is considered on time.
According to the information given, installment loans have a 30-day grace period. So, if Mrs. Dewhurst brings her car loan payment 15 days into the grace period, she will not have to pay a late fee to the bank. The grace period allows borrowers some extra time to make their payments without incurring any penalties.