Sarah buys one red can of paint every month. If she continues this for four months, how many red cans did she buy?

Correct Answer: C

Rationale: The correct answer is C. Sarah buys one red can of paint every month for four months. Therefore, if she continues this pattern for four months, she would have bought a total of 4 red cans. Choices A, B, and D are incorrect because they do not reflect the total number of red cans accumulated over the specified period of four months.

Correct Answer: C

Rationale: To calculate the circumference of a circle, use the formula 2πr, where r is the radius. In this case, with a radius of 3 inches, the estimated circumference would be 2 x π x 3 = 6π ≈ 18.85 inches. Therefore, the best estimate for the circumference of the frame is 18 inches (Choice C). Choice A (12 inches) is too small as it corresponds to the diameter rather than the circumference. Choice B (16 inches) and Choice D (24 inches) are also incorrect as they do not reflect the accurate calculation based on the given radius.

Correct Answer: A

Rationale: The student's score is calculated by adding the points earned for correct answers (x) and subtracting the points lost for incorrect answers (y/2). Therefore, the expression for the student's score on the exam is x - y/2. Option A is correct because it accurately represents this calculation. Option B (x - y) is incorrect as it does not account for the penalty of losing half a point for each incorrect answer. Option C (30 - (x + y)) is incorrect as it subtracts the total number of questions from the sum of correct and blank answers, which does not represent the scoring system. Option D (30 - x - y/2) is also incorrect as it incorrectly subtracts x from 30 and then deducts y divided by 2, which is not the correct scoring method for the exam.

Correct Answer: A

Rationale: When the sampling distribution of means is plotted, the distribution tends to be approximately normal, especially as the sample size increases. This phenomenon is described by the Central Limit Theorem, which states that the sampling distribution of the sample mean will be normally distributed regardless of the shape of the original population distribution as long as the sample size is sufficiently large. Choices B and C are incorrect because sampling distributions of means are not skewed. Choice D is incorrect because there is a predictable shape to the distribution, which is approximately normal.

Correct Answer: C

Rationale: The equation y = 40x represents John's Gym charging $40 per month, while the equation y = 45x represents Ralph's Recreation Room charging $45 per month. Since $40 is less than $45, it can be concluded that John's Gym offers a lower monthly membership fee compared to Ralph's Recreation Room. Therefore, the correct answer is that John's monthly membership fee is less than Ralph's monthly membership fee. Choices A and B are incorrect because John's fee is not equal to or greater than Ralph's fee. Choice D is incorrect as there is a clear relationship indicating that John's monthly membership fee is less than Ralph's monthly membership fee.