QUESTION 18 Suppose it is known that the income distribution in a particular region is right-skewed and bimodal If bank economists are interested in estimating the mean income, which of the following is true? 0 Provided that the sample size is sufciently large. the sampling distribution will be approximately Normal with a mean equal to the population mean. 0 Provided that the sample size is sufciently large. the sampling distribution will be approximately Normal with a standard deviation equal to the population standard deviation. 0 The sampling distribution will also be right-skewed for large sample sizes. O The standard deviation ofthe sampling distribution of will be proportionally larger than the population standard deviation, depending on the size of the sample. QUESTION 19 An army depot that overhauls ground mobile radar systems is interested in improving its processes One problem involves troubleshooting a particular component that has a high failure rate after it has been repaired and reinstalled in the system. The shop oor supervisor believes that having standard work procedures in place will reduce the time required for troubleshooting this component. Time (in minutes) required troubleshooting this component without and with the standard work procedure is recorded for a sample of 19 employees. Assuming that we define our differences as Time without standard work procedure - Time with standard work procedure, and the p-value associated with the test statistic is less than 0.0001. At alpha = 0.05, I. we reject the null hypothesis II. we fail to reject the null hypothesis III. we can conclude that having standard work procedures in place reduces troubleshooting time for this component 0 Ionly 0 II only O III only O land \"I Q U ESTI ON 20 City officials want to estimate the proportion of visitors who are repeat visitors to the city parks. They take a sample of 400 visitors and nd that 100 are on a second visit. The 99% condence interval is 0.1942 to 0.3053. What is the correct interpretation ofthe interval? O The proportion of repeat visitors is between 19.42% and 30.58% 0 The probability is 95% that between 19.42% and 30.58% of visitors are on a second visit 0 We are 99% condent that between 19.42% and 30.58% ofvisitors are on a second visit 0 The margin of error is between 19.42% and 30.58% QUESTION 21 The scatterplot does not inform the following about the relationship between two variables O Direction of association O Form of relationship 0 Strength of relationship 0 Predict the value of one variable based on the value of another variable