In general, if the variance of the difference scores decreases, what will happen to the value of the t statistic? a. It will increase in magnitude (move farther toward the tail of the distribution). b. It will decrease in magnitude (move toward 0 at the center of the distribution). c. It will stay the same; the t statistic is not affected by the variance of the difference        scores. d. It may increase or may decrease; there is no consistent relationship between variance and the size of the t statistic.

The Variance of Population for the following data:X = 155, 175, 125, 155, 175, %3D 195, 185, 525, 255, 425, 355, 455 is : * O 19350 O 15403 O 18600 O 17400

Students in an experimental psychology class did research on depression as a sign of stress. A test was administered to a sample of 30 students. The scores are given. Complete parts (a) through (c) below. 44 43 32 17 32 43 38 15 58 46 54. 14 (a) Find the mean and median of the data. The mean is 27 34 41 53 31 23 GRAPE (Round to three decimal places as needed.) 48 31 35 28 33 25 28 53 34 28 16 37 19

The figure shows population density (people per square mile) for all states of a certain country. The states are divided into four geographical regions: A, B, C, and D. Answer the questions below. D- 0 100 200 300 400 500 600 700 800 900 1000 1100 People per Square Mile Why is it best to compare medians and interquartile ranges for these data, rather than comparing means and standard deviations? OA. These data are fairly symmetric and do not have outliers, and the median and interquartile range provide more reliable information in these circumstances. B. Some of these data have outliers and/or are skewed, and the median and interquartile range amplify the effects of outliers and skewness. OC. Some of these data have outliers and/or are skewed, and the median and interquartile range are resistant to outliers. OD. Some of these data have vastly different centers, and the median and interquartile range provide more reliable information in these circumstances. List the approximate median…