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, Ha: 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, Ha: 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, Ha: 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):
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P-Value
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A) One-tailed
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B) Two-tailed
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Computed
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Critical
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Reject
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Fail to Reject
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Reject
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Fail to Reject
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a)
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p = 0.12
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α = 0.05
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b)
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p = 0.03
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α = 0.05
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c)
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p = 0.001
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α = 0.01
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d)
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p = 0.01
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α = 0.001
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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.
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x
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Probability
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Weighted Value
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Deviation
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Deviation2
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Weighted Squared Deviation
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0
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1
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2
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3
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4
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5
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6
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7
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Total
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Please answer the following questions:
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a) Mean
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b) Variance
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c) Standard Deviation
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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