© 2013 Pearson Education, Inc. Active Learning Lecture Slides For use with Classroom Response Systems Introductory Statistics: Exploring the World through Data, 1e by Gould and Ryan Chapter 3: Numerical Summaries of Center and Variation Slide 3 - 1

True or False The Empirical Rule says that if the distribution is unimodal and symmetric, then approximately 68% of the observations (roughly two-thirds) will be within one standard deviation of the mean. A. True B. False Slide © 2013 Pearson Education, Inc. Response Counter

The Empirical Rule says that if the distribution is unimodal and symmetric, then the percent of observations that will be within two standard deviations of the mean is A. 68%. B. 95%. C. Nearly all. D. None of the above. Slide © 2013 Pearson Education, Inc. Response Counter

True or False Standard units measure a value relative to the sample rather than with respect to some absolute measure. A. True B. False Slide © 2013 Pearson Education, Inc. Response Counter

True or False A measurement converted to standard units is called a z-score. A. True B. False Slide © 2013 Pearson Education, Inc. Response Counter

True or False A measurement with a z-score of 1.0 is one standard deviation above the mean. A. True B. False Slide © 2013 Pearson Education, Inc. Response Counter

True or False A measurement with a z-score of –1.4 is 1.4 standard deviations above the mean. A. True B. False Slide © 2013 Pearson Education, Inc. Response Counter

True or False z-Scores allow us to compare observations in one group with those in another, even if the two groups are measured in different units or under different conditions. A. True B. False Slide © 2013 Pearson Education, Inc. Response Counter

If you were to sort the data from smallest to largest, the data value that would be right in the middle is the A. Mean. B. Median. C. Mode. D. Range. Slide © 2013 Pearson Education, Inc. Response Counter

True or False The median cuts a distribution down the middle, so about 50% of the observations are below it and about 50% are above it. A. True B. False Slide © 2013 Pearson Education, Inc. Response Counter

True or False The median value represents a “typical” value in a data set. A. True B. False Slide © 2013 Pearson Education, Inc. Response Counter