MATH 109 Lecture Notes - Lecture 5: Standard Deviation
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Why more than one measure of center: extreme values (such as outliers) can distort the average. When there are many outliers, statisticians often use the median: a related anecdote. In 1984, the university of virginia announced that its department of. The salary of ralph sampson (nba player) was an outlier. The average as well as median are both measures of location the center . Root-mean-square (r. m. s: consider the following list of numbers. To find the typical size, one can ignore the sign of those numbers and the average of those numbers to determine their size. That would make 4. 6 (typical mean: however, statisticians use a quantity called rms to measure the typical size. Finally, take the square root of the mean (0+25+64+49+9)/5=29. 4. Each of the numbers 103,96, 101, 104 is almost 100 but is off by some amount. =3. 24: each of the numbers 103,96, 101, 104 has an average.
