Answer: The required cost of 12 pounds of apples is $18.
Step-by-step explanation: Given that the following table shows the price of apples in the local market :
Apples (pounds) 4 8 12 16
Price (dollars) 6 12 ? 24
We are to find the price of 12 pounds of apples.
Let x and y represents the quantity of apples in pounds and the corresponding price in dollars respectively.
Then, according to the given information, the points (4, 6) and (8, 12) will lie on the linear relation between x and y.
So, the slope of the line will be

Since the line passes through the point (4, 6), so its equation will be

Therefore, if x = 12, then we get

Thus, the required cost of 12 pounds of apples is $18.