Answer: $0.3 per lb per year.
Step-by-step explanation:
We know that the rate of change in price is given by :-
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Given: The price of apples went from $1.99 per lb to $3.19 per lb in four years.
Change in price =@@MATH_TOKEN_1@@
Time = 4 years
Now, the rate of change of the price of apples is given by :-
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Hence, the rate of change of the price of apples= $0.3 per lb per year.