500 câu trắc nghiệm Kinh tế lượng – 3A
11) In one town, 70% of adults have health insurance. What is the probability that 6 adults selected at random from the town all have health insurance?
○ 0.086
○ 4.2
● 0.118
○ 0.7
12) A IRS auditor randomly selects 3 tax returns from 49 returns of which 9 contain errors. What is the probability that she selects none of those containing errors?
○ 0.0046
● 0.5363
○ 0.0062
○ 0.544
Provide a written description of the complement of the given event.
13) When several textbooks are returned from editing, none of the books are found to be errorless.
● At least one of the textbooks is errorless.
○ None of the textbooks are errorless.
○ All of the textbooks are errorless.
Find the indicated probability.
14) A study conducted at a certain college shows that 64% of the school’s graduates find a job in their
chosen field within a year after graduation. Find the probability that among 6 randomly selected graduates, at least one finds a job in his or her chosen field within a year of graduating.
○ 0.167
○ 0.931
○ 0.640
● 0.998
15) The table below shows the soft drinks preferences of people in three age groups.
| cola | root beer | lemon-lime | |
| under 21 years of age | 40 | 25 | 20 |
| between 21 and 40 | 35 | 20 | 30 |
| over 40 years of age | 20 | 30 | 35 |
If one of the 255 subjects is randomly selected, find the probability that the person is over 40
years of age.
○ 1/2
● 1/3
○ 2/5
○ 3/5
16) The following table contains data from a study of two airlines which fly to Small Town, USA.
| Number of flights which were on time | Number of flights which were late | |
| Podunk Airlines | 33 | 6 |
| Upstate Airlines | 43 | 5 |
If one of the 87 flights is randomly selected, find the probability that the flight selected is an Upstate Airlines flight given that it was late.
○ 5/48
● 5/11
○ 5/87
○ None of the above is correct.
Solve the problem.
17) A firm uses trend projection and seasonal factors to simulate sales for a given time period. It
assigns “0” if sales fall, “1” if sales are steady, “2” if sales rise moderately, and “3” if sales rise a lot. The simulator generates the following output.
0 1 0 2 2 0 0 1 2 3 2 0 2 0 2 2 1 2 3 1 2 2 2 0 3 0 0 2 1 2 1
Estimate the probability that sales will rise at least moderately.
○ 0.512
○ 0.452
● 0.516
○ 0.613
Evaluate the expression.
18) \(C_2^{10}\)
○ 80,640
○ 40,320
● 45
○ 5
Solve the problem.
19) A state lottery involves the random selection of six different numbers between 1 and 22. If you select one six number combination, what is the probability that it will be the winning combination?
● 1/74,613
○ 1/113,379,904
○ 1/53,721,360
○ 1/720
20) How many 5-digit numbers can be formed using the digits 1, 2, 3, 4, 5, 6, 7 if repetition of digits is not allowed?
○ 120
○ 16,807
● 2520
○ 119