1 We expect that as the number of whiskey drinks consumed increases the amount of time to tie your shoelaces increases. If we execute a regression to predict the average number of seconds to tie the shoelaces using the number of whiskey rinks consumed, then what would be the appropriate Ho and Ha regarding B1. Ho: B1 = 0 and Ha: B1 < 0 Ho: B1 = 0 and Ha: B1 0 Ho: B1 = 0 and Ha: B1 > 0 3 points QUESTION 2 The standard deviation of Y is 100. The square root of the sum of the squared residuals divided by n-2 equals 15. Does this suggest that regression fits the data well or that it does not fit the data well? Does not fit the data well. We cannot tell. Fits the data well. 4 points QUESTION 3 The regression line is as follows: Y = 0.50 - 0.25*X What is the relationship between X and Y? As X increases, Y decreases As X increases, Y increases We cannot tell. 3 points QUESTION 4 An ....... study observes individuals and measures variables of interest but does not attempt to influence the responses. Observational study Experiment 2 points QUESTION 5 The ..... in a statistical study is the entire group of individuals about which we want information. Population Convenience sampling Sampling distribution Sample 2 points QUESTION 6 What does SRS stand for? Simple Random Statistics Simple Random Sample 2 points QUESTION 7 We call a phenomenon ..... if individual outcomes are uncertain but there is nonetheless a regular distribution of outcomes in a large number of repetitions. Probability Random Event Subset 2 points QUESTION 8 The smaller p-value, the ...... the evidence against the null hypothesis provided by the data. Stronger Weaker 2 points QUESTION 9 The multiplication of z-score by the standard error gives us ..... Margin of error Confidence interval Sample size 2 points QUESTION 10 If we fail to accept the alternative hypothesis when in fact the alternative hypothesis is true, this is a ..... Type I error Type II error Power of the test 2 points QUESTION 11 If we do not know the standard deviation of the population, we use .... for hypothesis testing. Chi-squared distribution Student's t distribution Normal distribution 2 points QUESTION 12 In the comparison of two populations, the degree of freedom is equal to: n1 = the sample size of the first group n2 = the sample size of the second group The larger of n1-1 and n2-1 n1 + n2 - 2 The smaller of n1-1 and n2-1 2 points QUESTION 13 The South African mathematician John Kerrich, while a prisoner of war during World War II, tossed a coin 10000 times and obtained 5087 heads. Is this significant evidence at the 10% alpha level that the probability that Kerrich's coin comes up heads is not 0.5? No Yes 6 points QUESTION 14 You want to estimate p with 90% confidence and a margin of error less than or equal to 2%. For planning purposes, you are willing to use p* = 0.5. What is the sample size required? 1702 1706 1698 8 points QUESTION 15 A university financial aid office polled an SRS of undergraduate students to study their summer employment. Not all students were employed the previous summer. Here are the results for men and women: Men Women Employed 725 615 Not employed 82 92 Is there evidence that the proportion of male students employed during the summer differs from the proportion of female students who were employed? Test the hypothesis at alpha level = 10%. Yes No 6 points QUESTION 16 One possible effect of air pollution is genetic damage. A study designed to examine this problem exposed one group of mice to air near a steel mill and another group to air in a rural area group. Here are the data for a mutation at the Hm-2 gene locus: Location Mutation Steel mill air Rural air Total Yes 30 23 53 No 66 127 193 Total 96 150 Is there evidence to conclude that the location is related to the occurrence of mutations? Find the chi-square value and test the hypothesis at the alpha level of 0.05. (9.77, No, there is not evidence) (8.77, No, there is not evidence) (8.77, Yes, there is evidence) (9.77, Yes, there is evidence) 10 points QUESTION 17 People often lie when they are asked questions concerning drug use. This is an example of ... Non-response bias Sampling bias Confounding Response bias 2 points QUESTION 18 When the correlation coefficient, r, is close to negative one, .... There is a weak linear relationship between the two variables There is no relationship between the two variables There is a strong linear relationship between the two variables 2 points QUESTION 19 The constant (intercept) in linear regression represents ... The expected x value when y is zero The expected y value when x is zero The strength of the relationship between x and y 3 points QUESTION 20 Which one of these statistics is resistant to outliers? Standard deviation Correlation coefficient Median Mean 2 points QUESTION 21 Which of the following are false statements? I. If there is sufficient evidence to reject a null hypothesis at the 1% level, then there is sufficient evidence to reject it at the 5% level. II. Whether to use a one- or two-sided test is typically decided after the data are gathered. III. If a hypothesis test is conducted at the 5% confidence level, there is a 5% chance of rejecting the null hypothesis I and II only I and III only I, II, and III II and III only