m7_12.3_solutions

12.3 Comparing Data Sets Math 7 Compare the data sets. 1. The heights of boys and girls are collected in a 7 th grade class. Boys: 56, 58, 59, 60, 62, 63, 64 Girls: 61, 68, 49, 52, 54, 52 BOYS GIRLS Shape Finish the bar graph and describe the shape No specific pattern Finish the bar graph and describe the shape Slightly skewed right Outlier Center Mean: Median: Mode: Mean: Median: Mode: 12.3 Practice

Spread Range: MAD: |56 െ 60.29 | ൌ 4.29 |58 െ 60.29| ൌ 2.29 |59 െ 60.29 | ൌ 1.29 |60 െ 60.29 | ൌ 0.29 |62 െ 60.29 | ൌ 1.71 |63 െ 60.29 | ൌ 2.71 |64 െ 60.29| ൌ 3.71 16.29 7 ൎ 2.327 Your answer will be more accurate if you used 60.2857 as the mean instead of the rounded 60.29. Range: MAD: |49 െ 56 | ൌ 7 |52 െ 56| ൌ 4 |52 െ 56 | ൌ 4 |54 െ 56 | ൌ 2 |61 െ 56 | ൌ 5 |68 െ 56 | ൌ 12 34 6 ൎ 5.6667 Based on the data sets, are boys taller than girls in this 7 th grade class? Explain!!!  The boys in this 7th grade class do appear to be taller. The average for boys is 60.29 versus the girls 56.  The girls average is being pulled up by one tall girl. 68 inches is an outlier so we should compare the medians in which the boys is taller.  Also, the boys tend to be grouped together more closely than the girls. Both the girls range and MAD is bigger than the boys which means the girls have more variability in their data. 2. The test scores of two 7 th grade classes are shown below. CLASS 1 CLASS 2 Shape Slightly skewed right No specific pattern Outlier 82,82,84,84,84,86,86,86,86,87,87,87,88,88,89,89,90,90,92,93,96,97,98,98 81,84,84,84,86,88,88,89,89,90,90,90,90,91,92,92,94,94,94,98,99,100,100,100