Copyright ©2013, 2010, 2007, 2004 by W. H. Freeman and Company The Basic Practice of Statistics, 6 th Edition David S. Moore, William I. Notz, Michael A. Fligner Figure 3.1 Histogram of the Iowa Test vocabulary scores of all seventh-grade students in Gary, Indiana. The smooth curve shows the overall shape of the distribution.

Copyright ©2013, 2010, 2007, 2004 by W. H. Freeman and Company The Basic Practice of Statistics, 6 th Edition David S. Moore, William I. Notz, Michael A. Fligner Figure 3.2a The proportion of scores less than or equal to 6.0 in the actual data is

Copyright ©2013, 2010, 2007, 2004 by W. H. Freeman and Company The Basic Practice of Statistics, 6 th Edition David S. Moore, William I. Notz, Michael A. Fligner Figure 3.2b The proportion of scores less than or equal to 6.0 from the density curve is The density curve is a good approximation to the distribution of the data.

Copyright ©2013, 2010, 2007, 2004 by W. H. Freeman and Company The Basic Practice of Statistics, 6 th Edition David S. Moore, William I. Notz, Michael A. Fligner Figure 3.4 The density curve for the location of accidents along a 5-mile bike path, for Exercise 3.2.

Copyright ©2013, 2010, 2007, 2004 by W. H. Freeman and Company The Basic Practice of Statistics, 6 th Edition David S. Moore, William I. Notz, Michael A. Fligner Figure 3.5a The median and mean of a symmetric density curve both lie at the center of symmetry.

Copyright ©2013, 2010, 2007, 2004 by W. H. Freeman and Company The Basic Practice of Statistics, 6 th Edition David S. Moore, William I. Notz, Michael A. Fligner Figure 3.5b The median and mean of a right-skewed density curve. The mean is pulled away from the median toward the long tail.

Copyright ©2013, 2010, 2007, 2004 by W. H. Freeman and Company The Basic Practice of Statistics, 6 th Edition David S. Moore, William I. Notz, Michael A. Fligner Figure 3.8 Two Normal curves, showing the mean  and standard deviation .

Copyright ©2013, 2010, 2007, 2004 by W. H. Freeman and Company The Basic Practice of Statistics, 6 th Edition David S. Moore, William I. Notz, Michael A. Fligner Figure 3.9 The 68–95–99.7 rule for Normal distributions.

Copyright ©2013, 2010, 2007, 2004 by W. H. Freeman and Company The Basic Practice of Statistics, 6 th Edition David S. Moore, William I. Notz, Michael A. Fligner Figure 3.10 The 68–95–99.7 rule applied to the distribution of Iowa Test scores for seventh-grade students in Gary, Indiana, for Example 3.2. The mean and standard deviation are  = 6.84 and  = 1.55.

Copyright ©2013, 2010, 2007, 2004 by W. H. Freeman and Company The Basic Practice of Statistics, 6 th Edition David S. Moore, William I. Notz, Michael A. Fligner

Copyright ©2013, 2010, 2007, 2004 by W. H. Freeman and Company The Basic Practice of Statistics, 6 th Edition David S. Moore, William I. Notz, Michael A. Fligner UN Figure 3.1

Copyright ©2013, 2010, 2007, 2004 by W. H. Freeman and Company The Basic Practice of Statistics, 6 th Edition David S. Moore, William I. Notz, Michael A. Fligner

Copyright ©2013, 2010, 2007, 2004 by W. H. Freeman and Company The Basic Practice of Statistics, 6 th Edition David S. Moore, William I. Notz, Michael A. Fligner