A recent study reported that 18- to24-year-olds averaged 192 restaurant visits per year. Assume that the standard deviation for number of visits per year for this age group is 56.5.
To validate these findings, a random sample of forty 18- to 24-year-olds was selected and found to average 212 restaurant visits per year. Which of the following statements is correct?A) The interval that contains 95 of the sample means is 170.3 and 213.7 visits. Because the sample mean is between these two values, we have support for the results of the May 2011 study.
B) The interval that contains 95 of the sample means is 170.3 and 213.7 visits. Because the sample mean is between these two values, we do not have support for the results of the May 2011 study.
C) The interval that contains 95 of the sample means is 174.5 and 209.5 visits. Because the sample mean is not between these two values, we have support for the results of the May 2011 study.
D) The interval that contains 95 of the sample means is 174.5 and 209.5 visits. Because the sample mean is not between these two values, we do not have support for the results of the May 2011 study.
Q. 2The test statistic for the two-tail Wilcoxon signed-rank test is the larger of the sum of the negative signed ranks (R-) and the sum of the positive signed ranks (R+).
Indicate whether the statement is true or false
Q. 3________ adjusts the previous forecast with a portion of the previous period's forecasting error.
A) Simple moving average
B) Weighted moving average
C) Exponential smoothing
D) Multiplicative decomposition
Q. 4A random sample of 25 roundtrip flights between Philadelphia and Dallas has an average airfare of 393.50 with a sample standard deviation of 50.30. The critical value for an 80 confidence interval around this sample mean is ________.
A) 0.857
B) 1.318
C) 1.711
D) 2.064
Q. 5A study conducted by Harvard Business School recorded the amount of time CEOs devoted to various activities during the workweek. Meetings were the single largest activity averaging 18 hours per week.
Assume that the standard deviation for the time spent in meetings is 5.2 hours. To confirm these results, a random sample of 35 CEOs was selected. This sample averaged 16.8 hours per week in meetings. Which of the following statements is correct?A) The interval that contains 95 of the sample means is 16.3 and 19.7 hours. Because the sample mean is between these two values, we have support for the results of the CEO study by the Harvard Business School.
B) The interval that contains 95 of the sample means is 17.1 and 18.9 hours. Because the sample mean is not between these two values, we do not have support for the results of the CEO study by the Harvard Business School.
C) The interval that contains 95 of the sample means is 15.7 and 20.3 hours. Because the sample mean is between these two values, we have support for the results of the CEO study by the Harvard Business School.
D) The interval that contains 95 of the sample means is 15.7 and 20.3 hours. Because the sample mean is between these two values, we do not have support for the results of the CEO study by the Harvard Business School.
Quick Reply
