40 multiple choice questions of Econ

For questions 1-3:

Using the standard normal distribution table, compute the following probabilities:

P( Z ≥ 1.8) is:

.0359

.0062

.4938

.4641

Question 2 0.5 pts

P(Z ≤ 1.5) is:

.8750

.9599

.9332

.9938

Question 3 0.5 pts

P(1.34 ≤ Z ≤ 2.72) is:

.0868

.0476

.8746

.0309

Question 4 0.5 pts

Questions 4-6 are based on the following information:

Given that X ~N(μ=20, σ=5) compute the following probabilities:

P(X ≥ 25) is:

.5713

.1587

.3413

.2456

Question 5 0.5 pts

P(18 ≤ X ≤ 30) is:

.3218

.4332

.4632

.6326

Question 6 0.5 pts

P(X ≤ 20) is:

.347

.000

.500

.208

Question 7 0.5 pts

Questions 7-9 are based on the following information:

Scores on an achievement test are known to follow a normal distribution with mean 420 and standard deviation 80.

7. For a randomly chosen student taking the test, what is the probability of a score between 400 and 480?

.9772

.3862

.3721

.8413

Question 8 0.5 pts

What is the probability of a score that exceeds 340?

.9482

.6343

.8413

.9987

Question 9 0.5 pts

What is the probability of a score less than 300?

.0668

.0146

.4843

.8234

Question 10 0.5 pts

Using the normal distribution table find Z0 such that:

P( Z ≥ Z0 ) = .025

1.64

1.96

2.57

1.87

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Question 11 0.5 pts

P(-Z0 ≤ Z ≤ Z0) = .88

1.29

2.11

2.18

1.56

Question 12 0.5 pts

P(Z ≤ Z0) = .9868

1.96

-1.64

2.17

2.22

Question 13 0.5 pts

The random sample X is normally distributed with mean 40 and standard deviation 16. If n=256, compute the following probabilities:

13. P(x with bar on top ≥ 42) is:

.4938

.0062

.4772

.0228

Question 14 0.5 pts

P(37 ≤ x with bar on top ≤ 39) is:

.1574

.6286

.3413

.6826

Question 15 0.5 pts

P(x with bar on top ≥ 38) is:

.9772

.4772

.6038

.5080

Question 16 0.5 pts

Questions 16-18 are based on the following information:

A sample of n=400 observations is drawn from a population with mean μ=1,000 and σ=400. Find the following probabilities:

16. P(x with bar on top ≤1030) is:

.8405

.9772

.3896

.9332

Question 17 0.5 pts

P(960≤ x with bar on top ≤1020) is:

.8406

.8400

.8185

.1574

Question 18 0.5 pts

P(x with bar on top ≥ 1060) is:

.0567

.0023

.4356

.0013

Question 19 0.5 pts

Questions 19-22 are based on the following information

Given a population with three observations: 2, 4, and 6

19. The population mean μ of the observations is:

6

4

3

2

Question 20 0.5 pts

The population variance, Var(X)=σ2 of the observations is:

1/3

3/4

8/3

4/3

Question 21 0.5 pts

If a sample of n=2 data set is selected from this population of data, the mean of the sampling distribution of x with bar on top , that is E(x with bar on top) is:

7

6

3

4

Question 22 0.5 pts

If a sample of n=2 data set is selected from this population of data, the variance of the sampling distribution of x with bar on top, that is Var(x with bar on top) is:

1/3

2/3

4/3

8/3

Question 23 0.5 pts

The entire group of persons, places or items that we want to collect observations from is known as:

population

sample space

frame

sample

Question 24 0.5 pts

A sample wherein all items in a population have the same chance of being selected for inclusion in the sample is:

a random sample

a good sample

a population sample

a cluster sample

Question 25 0.5 pts

A sampling distribution of the sample statistic x with bar on top is:

a random sampling of x with bar on top

a probability distribution of x with bar on top

a population sampling of x with bar on top

a population distribution of x with bar on top

Question 26 0.5 pts

Questions 26-29 are based on the following information:

Scores of the first test in Econ 261 follow a normal distribution with mean 70 and standard deviation 5. Compute the following probabilities.

26. P(X≥60) is:

.9862

.9772

.0228

.1325

Question 27 0.5 pts

P(X≤85) is:

.6343

.4987

.9987

.9482

Question 28 0.5 pts

P(65 ≤ X ≤ 80) is:

.7843

.8185

.9146

.8234

Question 29 0.5 pts

P(X≤75) is:

.9482

.8413

.6343

.9987

Question 30 0.5 pts

Random samples of size 1600 are taken from a population whose mean is μ=120 and standard deviation σ=40. The mean and standard error of the sample mean (x with bar on top) are respectively:

(180, 102)

(120, 1)

(120, 2)

(40, 120)

Question 31 0.5 pts

For questions 31-38:

Using the standard normal distribution table, compute the following probabilities:

P( Z ≥ 1.65) is:

.4641

.0344

.0062

.0495

Question 32 0.5 pts

P(Z ≤ 2.34) is:

.8750

.9599

.9904

.9332

Question 33 0.5 pts

P(1.34 ≤ Z ≤ 2.72) is:

.0868

.8746

.0476

.0309

Question 34 0.5 pts

P( Z ≥ - 1.65) is:

.9713

.9505

.2456

.1587

Question 35 0.5 pts

P(-3 ≤ Z ≤ - 1.75) is:

.4332

.0388

.4632

.6218

Question 36 0.5 pts

P(Z ≤ 0) is:

.208

.347

.500

.000

Question 37 0.5 pts

P(-1.56 ≤ Z ≤ 0) is:

.4406

.1945

.3863

.9772

Question 38 0.5 pts

P(Z ≤ -1.35) is:

.1940

.3806

.3721

.0885

Question 39 0.5 pts

Random samples of size 100 are taken from a population whose mean is μ=70 and standard deviation σ=25. The mean and standard error of the sample mean (x with bar on top), respectively, are:

70 and 2.5

40 and 2.5

70 and 1

30 and 20

Question 40 0.5 pts

The standard deviation of x with bar on top is called:

the mean deviation of x with bar on top

the standard deviation of X

B. the standard deviation of the population

the standard error of x with bar on top