# 500 câu trắc nghiệm Kinh tế lượng – 6C

Tổng hợp 500 câu trắc nghiệm + tự luận Kinh tế lượng (Elementary Statistics). Tất cả các câu hỏi trắc nghiệm + tự luận đều có đáp án. Nội dung được khái quát trong 13 phần, mỗi phần gồm 3 bài kiểm tra (A, B, C). Các câu hỏi trắc nghiệm + tự luận bám rất sát chương trình kinh tế lượng, đặc biệt là phần thống kê, rất phù hợp cho các bạn củng cố và mở rộng các kiến thức về Kinh tế lượng. Các câu hỏi trắc nghiệm + tự luận của phần 6C bao gồm:

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. Provide an appropriate response.
1) How do you determine whether to use the z or t distribution in computing the margin of error,

$$E = {z_{\alpha /2}}\frac{\sigma }{{\sqrt n }}$$ or $$E = {t_{\alpha /2}}\frac{s}{{\sqrt n }}$$?

Use the normal (z) distribution if the population SD is known and the population is normally distributed or if the population SD is known and the sample size exceeds 30. Use the t distribution if the population SD is unknown and the population is normally distributed or if the population SD is unknown and the sample size exceeds 30

2) The Bide-a-While efficiency hotel, which caters to business workers who stay for extended periods of time (weeks or months), offers room service. In a small study of 35 randomly selected room service orders, the 95% confidence interval for mean delivery time for room service is 24.8 < $$\mu$$ < 29.6 minutes. The marketing director is trying to determine if she can advertise “room service in under 30 minutes, or the order is free.” How would you advise her?

We are 95% sure that the interval 24.8 < $$\mu$$ < 29.6 minutes contains the true mean. But it is incorrect to say mhas a 95% chance of falling within the specific limits of 24.8 and 29.6 minutes. Therefore, it would not be advisable to advertise room service in under 30 minutes

3) Explain how confidence intervals might be used to make decisions. Give an example to clarify your explanation.

Answers will vary, but for example: Suppose we have a confidence interval of 0.456 < $$\mu$$ < 0.462 for the
mean diameter of washers being being machined by the night shift of a plant. If the mean diameter is supposed to be 0.470, we can conclude that the process needs to be adjusted.

4) Why is $${s^2}$$ the best point estimate of $${\sigma ^2}$$?

$${s^2}$$ is unbiased, neither overestimating nor underestimating $${\sigma ^2}\, and \({s^2}$$ values are more consistent, having less variation about $${\sigma ^2}\. MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Solve the problem. 5) Find the value of -\({z_{\alpha /2}}$$ that corresponds to a level of confidence of 96.68 percent.
○ 2.13
○ -1.84
○ 0.0166
● -2.13

6) The following confidence interval is obtained for a population proportion, p: (0.283, 0.323). Use these confidence interval limits to find the point estimate $${\hat p}$$.
○ 0.323
○ 0.308
○ 0.283
● 0.303