****REMINDER: Test on the 19
th
!
Math Structures II
February 07, 2008
8.2: Measures of Central Tendency:
1. MEAN: (arithmetic mean, “average”)
Most Commonly seen as the letter “x” with a horizontal line on top of it (opposite
of being underlined)
= (x(subscript 1) + x (subscript 2) + X3 + X4 + X5….+Xn)/n
2. MEDIAN: value located exactly in the middle of the ordered set of data.
*If you have an odd number of values, median is the middle number.
*If you have an even number of values, the median is the average/mean of the 2
middle numbers.
3. MODE: the value that occurs the most.
Ex: {1,2,3,3,4,5,4,3} Mode = 3
*There may be no mode. “Mode= none”.
*There may be more than one mode. If so, it is referred to as bimodal
.
Ex: Find mean, median, and mode of distance drive from class. Take information from
table of information previously given in class.
1,1,2,2,2,2,3,3,4,5,5,5,7,10,10,12,15,20,30,30.
Mean: 169/20