Question

The accompanying data are the percentage of babies born prematurely in a particular year for the 50 U.S. states and the District of Columbia (DC).

State	Premature Percent	State	Premature Percent	State	Premature Percent
Alabama	11.4	Kentucky	10.4	North Dakota	8.1
Alaska	8.2	Louisiana	12.0	Ohio	10.0
Arizona	8.7	Maine	8.1	Oklahoma	10.0
Arkansas	9.7	Maryland	9.8	Oregon	7.4
California	8.0	Massachusetts	8.3	Pennsylvania	9.1
Colorado	8.1	Michigan	9.5	Rhode Island	8.3
Connecticut	8.9	Minnesota	8.4	South Carolina	10.5
Delaware	9.0	Mississippi	12.6	South Dakota	8.2
DC	9.3	Missouri	9.5	Tennessee	10.5
Florida	9.6	Montana	9.0	Texas	10.1
Georgia	10.5	Nebraska	8.8	Utah	8.8
Hawaii	9.7	Nevada	9.8	Vermont	7.6
Idaho	7.9	New Hampshire	7.9	Virginia	8.9
Illinois	9.8	New Jersey	9.3	Washington	7.8
Indiana	9.4	New Mexico	8.9	West Virginia	10.5
Iowa	9.0	New York	8.6	Wisconsin	8.9
Kansas	8.4	North Carolina	9.4	Wyoming	10.9

(a)

The smallest value in the data set is 7.4 (Oregon), and the largest value is 12.6 (Mississippi). Are these values outliers? Explain.

Any observations smaller than  % or larger than  % are considered outliers. Therefore, Oregon's data value (7.4%)  ---Select--- is is not an outlier and Mississippi's data value (12.6%)  ---Select--- is is not an outlier.

(b)

Construct a boxplot for this data set.

The box-and-whisker plot has a horizontal axis numbered from 7 to 13. The box-and-whisker is also horizontal. The left whisker is approximately 7.4, the left edge of the box is approximately 8.3, the line inside the box is approximately 9, the right edge of the box is approximately 9.8, and the right whisker is approximately 12. There is one outlier located at 12.6.

The box-and-whisker plot has a horizontal axis numbered from 7 to 13. The box-and-whisker is also horizontal. The left whisker is approximately 7.9, the left edge of the box is approximately 8.8, the line inside the box is approximately 9, the right edge of the box is approximately 9.3, and the right whisker is approximately 12.1. There are 2 outliers located at 7.4 and 12.6.

The box-and-whisker plot has a horizontal axis numbered from 7 to 13. The box-and-whisker is also horizontal. The left whisker is approximately 7.4, the left edge of the box is approximately 8.3, the line inside the box is approximately 9, the right edge of the box is approximately 9.8, and the right whisker is approximately 12.6.

The box-and-whisker plot has a horizontal axis numbered from 7 to 13. The box-and-whisker is also horizontal. The left whisker is approximately 7.9, the left edge of the box is approximately 8.3, the line inside the box is approximately 9, the right edge of the box is approximately 9.8, and the right whisker is approximately 12.6. There is one outlier located at 7.4.

Comment on the interesting features of the plot.

The boxplot shows  ---Select--- no outliers one outlier two outliers and the distribution is  ---Select--- negatively skewed approximately symmetric positively skewed . The minimum value is  %, the lower quartile is  %, the median is  %, the upper quartile is  %, and the maximum value is  %.

Answer 1

(a)

The smallest value in the data set is 7.4 (Oregon), and the largest value is 12.6 (Mississippi). Are these values outliers? Explain.

Any observations smaller than 6.175% or larger than 11.975% are considered outliers. Therefore, Oregon's data value (7.4%) is not an outlier and Mississippi's data value (12.6%) is an outlier.

(b)

Construct a boxplot for this data set.

Comment on the interesting features of the plot.

The boxplot shows two outliers and the distribution is positively skewed . The minimum value is 7.4%, the lower quartile is 8.35%, the median is 9%, the upper quartile is 9.8%, and the maximum value is 12.6%.