Final answer:
To calculate the value of the car at the end of the third year, linear depreciation is used to find an annual depreciation rate, which is then applied to the initial cost, resulting in a value of $20,400.
Step-by-step explanation:
The student asked for the value of an automobile at the end of the third year, given the initial purchase price and the value after 6 years. To solve this, we use linear depreciation. The car was initially worth $39,000 and depreciated to $1,800 after 6 years.
This gives us a total depreciation of $39,000 - $1,800 = $37,200 over 6 years. To find the annual depreciation, divide the total depreciation by 6, which gives $37,200 / 6 = $6,200 per year.
Then, to find the value at the end of the third year, we subtract three years' worth of depreciation from the initial value: $39,000 - (3 × $6,200) = $39,000 - $18,600 = $20,400.
Therefore, the car was worth $20,400 at the end of the third year.