# 500 câu trắc nghiệm Kinh tế lượng – 6A

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 6A bao gồm:

SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. Provide an appropriate response.
1) Define margin of error. Explain the relation between the confidence interval and the error estimate. Suppose a confidence interval is 9.65 < $$\mu$$ < 11.35. Find the sample mean $${\bar x}$$ and the error estimate E.

The margin of error is the maximum likely difference between the observed sample mean $${\bar x}$$ and the true value for the population mean $$\mu$$. The confidence interval is found by taking the sample mean $${\bar x}$$ and adding the margin of error E to find the high value and subtracting E to find the low value of the interval. In the interval 9.65 < $$\mu$$ < 11.35, the sample mean $${\bar x}$$ is 10.5 and the error estimate E is 0.85.

2) When determining the sample size for a desired margin of error, the formula is $$n = \frac{{z_{\alpha /2}^2\hat p\hat q}}{{{E^2}}}$$. Based on this formula, discuss the fact that sample size is not dependent on the population size; that is, it is not necessary to sample a particular percent of the population.

As shown in the formula, the appropriate sample size is dependent on the appropriate z score, the sample proportion, and the margin of error, not on N, the population size.

3) When determining sample size we need to know $${\hat p}$$. If we have no prior information, what are two methods that can be used?

Use a result from a prior study or use $${\hat p}$$ = 0.5.

4) Why would manufacturers and businesses be interested in constructing a confidence interval for the population variance? Would manufacturers and businesses want large or small variances?

Manufacturers and businesses would be interested in small variances — a consistent product. They would be interested in confidence intervals for the population variance to control consistency of their product.

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
Solve the problem.
5) Find the critical value $${z_{\alpha /2}}$$ that corresponds to a degree of confidence of 98%.
○ 2.575
● 2.33
○ 1.75
○ 2.05

Express the confidence interval in the form of $$\hat p \pm E$$
6)0.033 < p < 0.493
○ $${\hat p}$$ = 0.23 ± 0.5
● $${\hat p}$$ = 0.263 ± 0.23
○ $${\hat p}$$ = 0.263 ± 0.5
○ $${\hat p}$$ = 0.23 ± 0.6