Nokea
When the sampling distribution of means is plotted, which of the following is true?
- A. The distribution is approximately normal.
- B. The distribution is positively skewed.
- C. The distribution is negatively skewed.
- D. There is no predictable shape to the distribution.
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.
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What is the solution to 4 x 7 + (25 - 21)²?
- A. 512
- B. 36
- C. 44
- D. 22
Correct Answer: C
Rationale: To find the solution, first solve the expression inside the parentheses: 25 - 21 = 4. Then, square the result from the parentheses: 4² = 16. Next, perform the multiplication: 4 x 7 = 28. Finally, add the results: 28 + 16 = 44. Therefore, the correct answer is 44. Choice A (512), Choice B (36), and Choice D (22) are incorrect as they do not follow the correct order of operations for solving the given mathematical expression.
67 miles is equivalent to how many kilometers to three significant digits?
- A. 107 km
- B. 106 km
- C. 33 km
- D. 85 km
Correct Answer: A
Rationale: To convert miles to kilometers, the conversion factor is 1 mile ≈ 1.609 kilometers. Therefore, to convert 67 miles to kilometers, you would multiply: 67 miles 1.609 km/mile = 107.703 km. When rounded to three significant digits, this gives 108 km. Therefore, 67 miles is approximately 108 kilometers. Choice A is correct because it is the closest rounded value to three significant digits. Choices B, C, and D are incorrect as they do not match the calculated conversion of 108 km.
Bernard can make $80 per day. If he needs to make $300 and only works full days, how many days will this take?
- A. 2
- B. 3
- C. 4
- D. 5
Correct Answer: C
Rationale: To find out how many days Bernard needs to work to make $300, we divide the total amount he needs by how much he makes per day: $300 / $80 = 3.75 days. Since Bernard can only work full days, he would need to work for 4 days to make $300. Therefore, the correct answer is 4 days. Choice A (2 days) is incorrect because it does not match the calculation based on his daily earnings. Choice B (3 days) is incorrect as the calculated result is not a whole number, so Bernard needs to work for more than 3 days. Choice D (5 days) is incorrect as it exceeds the calculated number of days needed to make $300.
How much did he save from the original price?
- A. $170
- B. $212.50
- C. $105.75
- D. $200
Correct Answer: B
Rationale: To calculate the amount saved from the original price, you need to subtract the discounted price from the original price. The formula is: Original price - Discounted price = Amount saved. In this case, the original price was $850, and the discounted price was $637.50. Therefore, $850 - $637.50 = $212.50. Hence, he saved $212.50 from the original price. Choice A ($170) is incorrect as it is not the correct amount saved. Choice C ($105.75) is incorrect as it does not match the calculated savings. Choice D ($200) is incorrect as it is not the accurate amount saved based on the given prices.
What is the sixth number in the sequence 5, 6, 7, 8, 9?
- A. 8
- B. 10
- C. 11
- D. 12
Correct Answer: C
Rationale: In the given sequence 5, 6, 7, 8, 9, the sixth number would come after 9, not after the fifth number in the sequence. To find the sixth number, we need to continue the pattern after 9. The next number after 9 would be 10, making it the sixth number in the sequence. Therefore, the correct answer is not listed among the choices provided. Choice A, 8, is the fifth number in the sequence. Choice B, 10, is the number right after the sixth number. Choice D, 12, is not in the sequence at all, making it incorrect. Thus, the correct answer is 11.