True B. False For dependent samples, we assume the distribution of the paired differences between the populations has a mean greater than 0. A. True B. False For independent populations, the standard deviation of the distribution of the differences has a variance equal to the sum of the two individual variances.
1 Week 5 Exercises from the e-text 6/30/2012 5. State the main points of the Central Limit Theorem for a mean. The central limit theorem allows for the approximation of the shape of the sample. The central limit theorem is the mean of a sufficiently large number of independent random variables that will be approximately normally distributed. It also describes the characteristics of the population of the means which has been created from the means of an infinite number of random population samples.
Selected Answer: False Question 8 The Delphi develops a consensus forecast about what will occur in the future. Selected Answer: True Question 9 __________ is a measure of dispersion of random variable values about the expected value. Selected Answer: Standard Deviation Question 10 In Bayesian analysis, additional information is used to alter the __________ probability of the occurrence of an event. Selected Answer: Marginal Question 11 The __________ is the maximum amount a decision maker would pay for additional information. Selected Answer: Expected Value of Perfect Information Question 12 In the Monte Carlo process, values for a random variable are generated by __________ a probability distribution.
Statistics about the actual population rather than the target population B. Non-response bias C. Inability to perform inferential statistics D. Probability sampling When every member of a population has the chance of being selected based on the probability, or frequency, of its representation in that population, you are using which type of sampling? A. Quota sample B. Census sample C. Convenience sample D. Random sample Which of the following statements is NOT true? A. Estimating parameters is an important aspect of descriptive statistics. B.
Answer | | | | | Selected Answer: | False | Correct Answer: | False | | | | | * Question 6 2 out of 2 points | | | The Hurwicz criterion is a compromise between the maximax and maximin criteria. Answer | | | | | Selected Answer: | True | Correct Answer: | True | | | | | * Question 7 2 out of 2 points | | | Using the minimax regret criterion, we first construct a table of regrets. Subsequently, for each possible decision, we look across the states of nature and make a note of the maximum regret possible for that decision. We then pick the decision with the largest maximum regret. Answer | | | | | Selected Answer: | False | Correct Answer: | False | | | | | * Question 8 2 out of 2 points | | | The chi-square test is a statistical test to see if an observed data fit a
Roll a (fair, six-sided) Die: (4 possible points) a) If you roll a single die and count the number of dots on top, what is the sample space of all possible outcomes? Are the outcomes equally likely? Sample space: 1,2,3,4,5,6; They are equally likely. b) Assign probabilities to the outcomes of the sample space in part (a). Do the probabilities add up to 1?
According to the Central Limit Theorem, it will be bell shaped because it is normally distributed. We should not make any assumptions because the sample size is larger than 30 which conclude that all possible sample means are approximately normally distributed. Find the mean and the standard deviation of the sampling distribution of the sample mean x bar. Mean = 1/n x n x mean (x_1) = 20 Mean of sample means = 20 Standard deviation = x/n = 4⁄8= ½ Standard deviation of the sample means = ½ Calculate the probability that we will obtain a sample mean greater than 21; that is, calculate P(x bar>21). Hint: Find the z value corresponding to 21 by using μ_(x bar) and σ_(x bar) because we wish to calculate a probability about x bar.
RES/342--- This produced a 28/30 on the final 1) What are the critical z-values for a two-tailed hypothesis test if the significant level = 0.01? C. ± 2.58 2) In classical hypothesis testing, the test statistic is to the critical value what the __________. A. ‘p-value’ is to alpha 3) For a hypothesis test of a single population mean at 95% confidence level, a calculated Z score of 1.7 supports the conclusion that A. the population mean is greater than the hypothesized value 4) If the paired differences are normal in a test of mean differences, then the distribution used for testing is the C. student distribution 5) One hundred women were polled and 60 reported successfully communicating an automobile problem to an auto repairman. A sample of 150 men had 95 reporting the same success.
With increase in the number of test the reliability of a test increases. The Spearman-Brown Formula strengths is that it can specify how reliable a test is based on the test being increased or reduced. It also works in inverse telling a researcher how many points needed to append in order to achieve a defined reliability constant. The weakness of the Spearman-Brown formula is that it is only effectual with consistent test items that are include travail and duration. That is, only items that are the same.
Find the mean and the standard deviation of the sampling distribution of the sample mean of bar x. Mean = 20 (given in the question) Standard deviation = 4/√64 Standard deviation = 4/ 8 Standard deviation = 0.5 c. Calculate the probability that we will obtain a sample mean greater than 21; that is, calculate P(x > 21). Hint: Find the z value corresponding to 21 by using μ and σ because we wish to calculate a probability about x. Then sketch the sampling distribution and the probability Z = (21-20)/ (4/√64) Z = 1/0.5 Z = 2 P (z>2) P = 1-0.9772 P = 0.0228 d. Calculate the probability that we will obtain a sample mean less than 19.385 ; that is calculate P(x.< 19.385). Z = (19.385 - 20)/ (4/√64) Z = -0.615 / 0.5 Z = -1.23 P = 0.1093 7.30 On February 8, 2002, the Gallup Organization released the results of a poll concerning American attitudes toward the 19th Winter Olympic Games in Salt Lake City, Utah.