Question

i-1i0 (Two Choices: (a) or (b)) 1. One may decrease the power of a hypothesis test by increasing the sample size n. True (b) False 2, The Central Limit Theorem even applies to a sample meany from a population with a uniform distribution. (a) True (b) False 3. If events A, B, and Care all mutually-independent, then P(A u B u C) P(A) + P(B) + P(C (a) True (b) False 4. For any data set, at least half of the data will fall within 1 standard deviations of the mean. (a) True (b) False 5. In a hypothesis test setting, stating "the results are statistically significant" is equivalent to conch the alternative hypothesis. (a) True (b) False 6. In the city of Metropolis, the annual number of churches has a high positive corelation r wi annual number of homicides.If.81 and n 30, is there sufficient evidence to say that buildin churches in Metropolis causes an increase in homicides in Metropolis? (a) Yes (b) No 7. In hypothesis testing, a type I error is considered worse than a type II error. (a) True (b) False 8. Which of the following confidence levels leads to a larger confidence interval? (a) 90% (b) 95% (a) True (b) False 9. A chi-square test statistic is never negative. 10. If a population has a distribution with mean μ and standard deviation σ then E(X) μ and σ(X)-σ/ym (a) True (b) False

Answer 1

Answers-

1. True- Power of test is the probability of rejecting the null hypothesis when it is actually false. Thus the significance of test must decrease when sample size is increased. Hence the power of test decreases when sample size decreases.

2. True- Central limt theorem can be applied on any distribution given the sample size is large.

3. False- If events A, B and C are independent, then P(A and B and C) = P(A) * P(B) * P(C), not addition.

4. True- We know that the Empirical Rule or 68-95-99.7% Rule gives the approximate percentage of data that fall within one standard deviation (68%), two standard deviations (95%), and three standard deviations (99.7%) of the mean. Thus given statement is true.

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