Correct Answer: C

Rationale: The correct answer is C: 0.84. To convert a percentage to a decimal, you divide the percentage value by 100. In this case, 84% divided by 100 equals 0.84. Choice A, 0.042, is not the correct conversion of 84%. Choice B, 84%, is already in percentage form and needs to be converted to a decimal. Choice D, 0.42, is not the correct conversion of 84% either. Therefore, the correct decimal form of 84% is 0.84.

Correct Answer: B

Rationale: To find the sum of numbers from 1 to 6, we add them together: 1 + 2 + 3 + 4 + 5 + 6 = 21. Therefore, the correct answer is 21. Choice A (30) is incorrect because it is not the sum of the numbers 1 to 6. Choice C (15) is incorrect as it is the sum of numbers 1 to 5. Choice D (13) is incorrect as it is the sum of numbers 1 to 4, not 1 to 6.

Correct Answer: B

Rationale: The total number of faculty members is 15 teachers + 20 teaching assistants = 35. The ratio of faculty to students is then 35:200, which simplifies to 7:40. Further simplifying by dividing both numbers by 5 gives the ratio 4:20, which can be simplified to 4:17. Therefore, the correct ratio is 4:17. Choices A, C, and D are incorrect ratios and do not match the calculated ratio of faculty members to students in this scenario.

Correct Answer: A

Rationale: To convert feet to kilometers, you need to divide the number of feet by 3280.84 (the number of feet in a kilometer). Therefore, 4382 feet is equal to 4382/3280.84 ≈ 1.336 kilometers. Choice B, 14.376 kilometers, is incorrect as it seems to be a miscalculation. Choice C, 1.437 kilometers, is also incorrect, as it is slightly off from the correct conversion. Choice D, 13.336 kilometers, is significantly higher than the correct answer and does not align with the conversion factor.

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.