Correct Answer: C

Rationale: The correct answer is C. This statement demonstrates a negative correlation between two variables as it indicates that as tennis balls age, their bounce tends to decrease. In a negative correlation, as one variable increases, the other tends to decrease. Choices A, B, and D do not illustrate a negative correlation. Choice A describes a positive correlation, as playing baseball more is associated with having more hits. Choice B does not show a correlation but a general observation. Choice D also does not demonstrate a correlation; it simply states that older cars tend to have higher mileage, without implying a relationship between age and mileage.

Correct Answer: C

Rationale: The largest circle that can fit inside the rectangle would have a diameter of 8 cm, which means the radius is half of the diameter, thus 4 cm. The area of a circle is calculated using the formula A = πr², where r is the radius. Substituting the radius value into the formula, the area of the circle is π(4)² = 16π cm². Therefore, the correct answer is 16π cm². Choice A (18π cm²), B (10π cm²), and D (8π cm²) are incorrect because they do not represent the area of the largest circle that fits inside the given rectangle.

Correct Answer: A

Rationale: The ratio 4:3 implies that for every 4 oz of yogurt, there are 3 oz of toppings. To find the amount of yogurt when the friend has 4.5 oz of toppings, we use the proportion: (4/3) 4.5 = 6 oz. Therefore, the amount of yogurt in their dessert is 6 oz. Choices B, C, and D are incorrect as they do not reflect the correct calculation based on the given ratio.

Correct Answer: D

Rationale: The correct answer is 25 g. Pencils are usually lightweight, and their weight is measured in grams. 25 kg (choice A) is too heavy for a pencil. 25 cm (choice B) is a unit of length, not weight. 25 mg (choice C) is too light for a pencil, as pencils typically weigh more than milligrams.

Correct Answer: C

Rationale: To convert milliliters (mL) to liters (L), you divide by 1000 since 1000 mL is equivalent to 1 liter. Therefore, 2500 mL is equal to 2.5 liters (2500 mL · 1000 = 2.5 L). Choice A (0.25 L) is incorrect as it represents a conversion error by a factor of 10. Choice B (25 L) is incorrect as it incorrectly multiplies instead of dividing by 1000. Choice D (250 L) is incorrect as it overestimates the conversion by a factor of 100.