STAT 2004 Lecture Notes - Lecture 5: Quartile, Ap Statistics, Interquartile Range

• School: Virginia Tech
• Department: Statistics
• Course: STAT 2004
• Professor: JW Brown

Document Summary

Midrange: averaging the maximum and minimum values in an attempt to identify the center of a histogram. Mean: the balancing point on a histogram. Median: the middle area that divides a given histogram into two equal areas: for skewed data, it is better to report the median than the mean. Finding the median mathematically: (cid:1858) (cid:1866) (cid:1871) (cid:1867)(cid:1856)(cid:1856) (cid:1857)(cid:1856)(cid:1853)(cid:1866)= (cid:3041)+(cid:2869)(cid:2870) ,(cid:1875) (cid:1857)(cid:1870)(cid:1857) (cid:1866) (cid:1871) (cid:1872) (cid:1857) (cid:1866)(cid:1873)(cid:1865)(cid:1854)(cid:1857)(cid:1870) (cid:1867)(cid:1858) (cid:1866)(cid:1873)(cid:1865)(cid:1854)(cid:1857)(cid:1870)(cid:1871) (cid:1858) (cid:1866) (cid:1871) (cid:1857)(cid:1874)(cid:1857)(cid:1866) (cid:1857)(cid:1856)(cid:1853)(cid:1866)=(cid:1856)(cid:1856)(cid:1864)(cid:1857) (cid:1853)(cid:1864)(cid:1873)(cid:1857)(cid:2869)+(cid:1856)(cid:1856)(cid:1864)(cid:1857) (cid:1853)(cid:1864)(cid:1873)(cid:1857)(cid:2870) 2: one can describe spread by looking at different quartiles, interquartile range: often represented by simply iqr" = upper quartile lower quartile. Spread: maximum, quartile 3, median, quartile 1, minimum, modified boxplots more accurately express the full data, as outliers are included as small dots. Boxplot: includes the information from the five-number summary. Only appropriate for symmetric data (cid:1871)(cid:3051)= (cid:4666)(cid:3052) (cid:3052) (cid:4667)2 (cid:3041) (cid:2869)