A professor wants to know whether or not there is a difference in comprehension of a lab assignment among students depending on if the instructions are given all in text, or if they are given primarily with visual illustrations. She randomly divides her class into two groups of 15, gives one group instructions in text and the second group instructions with visual illustrations. The following data summarizes the scores the students received on a test given after the lab. Let the populations be normally distributed with a population standard deviation of 5.32 points for both the text and visual illustrations.

Text (Group 1) Visual Illustrations (Group 2)

57.3 59

45.3 57.6

87.1 72.9

61.2 83.2

43.1 64

87.3 76.7

75.2 78.2

88.2 64.4

67.5 89

86.2 72.9

67.2 88.2

54.4 43.8

93 97.1

89.2 95.1

52 84.1

Is there evidence to suggest that a difference exists in the comprehension of the lab based on the test scores? Use=0.10.

Enter the test statistic - round to 4 decimal places.

Test Statistic z =___