PNB 2XE3 Chapter Notes - Chapter 5: Box Plot, Descriptive Statistics, Standard Deviation
4 Feb 2015
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Winter 2015: katz, lautenshlager, blackurn and harris (1990) performed a study on test performance. One group of students the nopassage group answered questions without seeing the passage on which the questions were based. A second group of students the passage group read the passage before answering questions. For these data, the mean = 46. 57, the range = 57 34 = 23, the variance = 46. 62, and the standard deviation = 6. 83. 91: calculate the mean, range, variance and standard deviation for the passage group (show your work). Variance = (x xbar )2 (n 1) (66 70. 18) 16: for each group, what percentage of the scores falls within 2 standard deviations of the mean? s=10. 61. Therefore, 16/17 or 94% of the scores fall within 2 standard deviations of the mean. Winter 2015: recalculate the mean and standard deviation for the first 7 numbers of the passage group data set (in bold).
