500 câu trắc nghiệm Kinh tế lượng – 13C
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 13C bao gồm:
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. Provide an appropriate response.
1) Describe a run chart and give an example. Refer to the values on each of the axes as you describe the run chart.
A run chart is a sequential plot of individual data values over time. The horizontal axis typically is used for the time sequence, and the vertical axis is used for the values of the data.
2) Describe a control chart. Complete the table to identify the important parts of different types of control charts.
| Points plotted | Center line and how to compute | Upper control limit | Lower control limit |
| Control chart for R | |||
| Control chart for \({\bar X}\) | |||
| Control chart for p |
A control chart of a process characteristic (such as a mean or range) consists of values plotted sequentially over time, and it includes a center line, representing a central value of the characteristic measurement, as well as lower and upper control limits, representing boundaries used to separate and identify any points considered to be unusual.
Construct a run chart for individual values corresponding to the given data.
3) A machine is supposed to fill boxes to a weight of 50 lbs. Every 30 minutes a sample of four
boxes is tested; the results are given below.
| S | A | M | R |
| 1 | 49 38 39 45 | 42.75 | 11 |
| 2 | 52 51 43 61 | 51.75 | 18 |
| 3 | 56 60 32 52 | 50 | 28 |
| 4 | 44 59 46 49 | 49.5 | 15 |
| 5 | 51 61 48 45 | 51.25 | 16 |
| 6 | 45 50 46 48 | 47.25 | 5 |
| 7 | 52 51 45 55 | 50.75 | 10 |
| 8 | 40 50 53 48 | 47.75 | 13 |
| 9 | 48 67 60 51 | 56.5 | 19 |
| 10 | 43 50 50 47 | 47.5 | 7 |
| 11 | 48 30 38 39 | 38.75 | 18 |
| 12 | 50 46 48 53 | 49.25 | 7 |
| 13 | 50 58 56 64 | 57 | 14 |
| 14 | 47 52 47 49 | 48.75 | 5 |
| 15 | 52 57 58 52 | 54.75 | 6 |
Construct an R chart and determine whether the process variation is within statistical control.
4) A machine that is supposed to produce ball bearings with a diameter of 7 mm yields the following data from a test of 5 ball bearings every 20 minutes.
| S | A | M | R |
| 1 | 6.3 6.8 6.9 6.8 6.9 | 6.74 | 0.6 |
| 2 | 6.3 6.6 6.6 6.3 7.0 | 6.56 | 0.7 |
| 3 | 6.8 6.7 7.0 6.5 7.0 | 6.8 | 0.5 |
| 4 | 7.0 6.7 6.7 6.8 6.8 | 6.8 | 0.3 |
| 5 | 6.8 6.8 6.6 6.5 6.4 | 6.62 | 0.4 |
| 6 | 6.8 6.7 6.6 6.3 6.9 | 6.66 | 0.6 |
| 7 | 7.3 7.3 7.4 7.4 7.0 | 7.28 | 0.4 |
| 8 | 7.2 7.0 7.2 6.9 7.1 | 7.08 | 0.3 |
| 9 | 7.3 7.6 7.1 7.4 7.6 | 7.4 | 0.5 |
| 10 | 7.2 7.6 7.5 7.6 7.1 | 7.4 | 0.5 |
| 11 | 7.2 7.2 7.4 7.0 7.0 | 7.16 | 0.4 |
| 12 | 7.5 7.4 7.4 7.6 7.1 | 7.4 | 0.5 |
Construct a control chart for \({\bar x}\).