Reference no: EM131016897

Part A: Multiple Choice (1-13)

1. The cumulative probability distribution of a random variable X gives the probability that X is __ to , some spacified value of X.

a. Greater than or equal   c. Less than or equal

b. Equal                        d. None of the above

2. What is the probability of P(-1.4 < Z < 0.6)?

a. 0.9254   c. 0.3427

b. 0.6449   d. 0.9788

3. By using the binomial table, if the sample size is 20 and p equals to 0.70, what is the value for P(X18)?

a. 0.0279   c. 0.1820

b. 0.0375   d. 0.1789

4. In a standard normal distribution, what is the area which lies between Z = -1.72 and Z = 2.53?

a. 0.8948   c. 0.9516

b. 0.9123   d. 0.8604

5. What is the value for 95% confidence interval for  if  = 7.3, x = 84.2, and n = 40.

a. 81.93786.463   c. 74.09379.337

b. 68.76772.033   d. 61.36466.846

6. The ____ is the smallest level of significance at which H₀ can be rejected.

a. value of α   c. p value

b. probability of committing of Type I error  d. value of 1- α

7. We say that sample results are significant when .

a. H₀ is not rejected

b. H₀ is rejected

c. is smaller than the p value

d. the computed value of the test statistic falls in the acceptance region

8. We commit a Type 1 error if we a true null hypothesis.

a. fail to reject   c. reject

b. accept d. compute

9. Given:H₀: µ = 10, H_a: µ ≠ 10, n = 12, α  = 0.01, and the computed test statistic is 2.394, the p value for the test is .

a. between 0.02 and 0.01 b. between 0.025 and 0.01

c. between 0.05 and 0.02 d. none of the above

10. We say that sample results are significant when .

a. H₀ is not rejected

b. H₀ is rejected

c. is smaller than the p value

d. the computed value of the test statistic falls in the acceptance region

11. You perform a hypothesis test about a population mean on the basis of the following information: n = 50,  = 100, α = 0.05, s = 30, H_a: µ < 110.  The computed value of the test statistic is .

a. -2.3570 b. -1.645

c. 2.3570 d. 4.24264

12. Given: H₀: µ  ≥ 100, the alternative hypothesis is if the test is one-sided and the critical value is negative.

a. µ < 100 b. µ > 100

c. µ = 100 d. µ ≠220

13. You perform a hypothesis test about a population mean on the basis of the following information: The sampled population is normally distributed with a variance of 100, n= 25, = 225, α = 0.05, H_a: µ > 220.  The critical value of the test statistic is _

a. 2.5   b. 1.645

c. 1.7109 d. 1.96

Part B: Fill in the blank Question number (14-24)

14. The purpose of hypothesis testing is to aid the manager or researcher in reaching a (an) concerning a (an) _ by examining the data contained in a (an) from that _____.

15. A hypothesis may be defined simply as _____ .

16. There are two statistical hypotheses. They are the ______ hypothesis and the _____ hypothesis.

17. A Type I error occurs when the investigator _____.

18. Values of the test statistic that separate the acceptance region from the rejection are called _____values.

19. The probability of obtaining a value of the test statistic as extreme as or more extreme than that actually obtained, given that the tested null hypothesis is true, is called for the _______ test.

20. When one is testing H₀: µ= µ₀ on the basis of data from a sample of size n from a normally distributed population with a known variance of σ², the test statistic is ____.

21. The null hypothesis contains a statement of _____.

22. The statement µ ≥ 0 is an inappropriate statement for the hypothesis ______.

23. The null hypothesis and the alternative hypothesis are ____ of each other.

24. Please consider "reject" or "fail to reject" by using one tailed and two-tailed method (Part A&B):

	P-Value		A)    One-tailed		B)     Two-tailed
	Computed	Critical	Reject	Fail to Reject	Reject	Fail to Reject
a)	p = 0.12	α = 0.05
b)	p = 0.03	α = 0.05
c)	p = 0.001	α = 0.01
d)	p = 0.01	α = 0.001

Part C: Answer the following questions (25-28)

25. Explain the differences between discrete random variable and continuous random variable.

26. What are the characteristics of discrete probability distribution?

27. When should the z-test be used and when should t-test be used?

28. Explain the following concept:

a) Central Limit Theorem

b) Type I error and Type II error

Part D: Must show all your work step by step in order to receive the full credit; Excel is not allowed. (29-39)

29. The random variable X has a normal distribution with mean 50 and variance 9. Find the value of X, call it:

30. Use problem number 3 on page 6-23 to fill in the table and answer the following questions.

x	Probability	Weighted Value	Deviation	Deviation2	Weighted Squared Deviation
0
1
2
3
4
5
6
7
Total

Please answer the following questions:

a)      Mean	b)      Variance	c)      Standard Deviation

31. Work on problem number 5 of page 6-14 (a-e).

32. Work on problem number 12 (a-e) on page 6-16

33. Use the following information to conduct the confidence intervals specified to estimate μ.

a. 95% confidence; =25, = 12.25, and n=60.

b. 98% confidence; =119.6, = 570.7321, and n=25.

34. Given the following probabilities, find Z0 and please draw the shading the area:

Show your work                          Please draw graphs

35. Work problem number 9 on page 7-47.

Show your work                           Please draw graphs

Attachment:- exam_ii_fall_2015.pdf