ANTH 383 Lecture Notes - Lecture 3: Interquartile Range, Standard Deviation, Quartile
Document Summary
Trimmed mean: computed as an ordinary mean but with a pre-specified percentage of the extremes is omitted first. The left-most (lowest) 5% and right-most (highest) 5% of the data are excluded, and from remaining mean is found. Measures of dispersion tells about edges of data. Range which is also affected by outliers. Quartiles: the three values in a distribution that partition it into four parts with an equal number of values in each part. Referred to as q1 q2 and q3, with 25% less than q1, 50% less than q2 and 75% less than q3. Similar to calculating the median the data values are listed in increasing order and the list is quartered. Interquartile range: the difference between q1 and q3. Quartile deviation: interquartile range divided by two. Percentiles divide into 100 pieces rather than 4 like quartiles. Generally use standard deviation rather than mean deviation.
