4. An acre is equal to 43,560 square feet, and there are 5280 feet in a mile. If a farm has the shape of a rectangle measuring 0.9 miles by 1.5 miles, what is the area of the farm in acres?
(a) 0.164 acre
(b) 11.14 acres
(c) 864 acres
(d) 1050 acres
Answer
\( \text{Convert square feet to acres: } \frac{37635840 \text{ square feet}}{43560 \text{ square feet/acre}} = 864 \text{ acres} \)
Step 1 ：\( \text{Convert miles to feet: 0.9 miles} \times 5280 \text{ feet/mile} = 4752 \text{ feet, 1.5 miles} \times 5280 \text{ feet/mile} = 7920 \text{ feet} \)
Step 2 ：\( \text{Calculate area in square feet: } 4752 \text{ feet } \times 7920 \text{ feet} = 37635840 \text{ square feet} \)
Step 3 ：\( \text{Convert square feet to acres: } \frac{37635840 \text{ square feet}}{43560 \text{ square feet/acre}} = 864 \text{ acres} \)
