Class+Notes

9/12/11 **Measures of Central Tendency (Lesson 1-4)**


 * Measures of Central Tendency** - Numbers that represent a set of data, these include the mean, median, and mode


 * Mean**- The mean is the sum of the data divided by the numbers of pieces of data.


 * Median**- The median is the middle number. Must re-write data from least to greatest first. If you have 2 medians you have to get the mean of the 2 numbers (add the two numbers and divide by 2) to determine the median.


 * Mode**- The mode is the number or item that appears most often, there can be more than 1 mode or there can be no mode.


 * Outlier**- an outlier is the number in the data set that is way off all the other numbers.


 * Range**- the range is the difference between the highest and the lowest number.

Find the mean, median, mode, outlier, and the range for each set of data:

A) 12, 7, 30, 2, 4 __

B) 1, 16, 3, 5, 1, 3, 2, 4, 1

HW: p. 19: #s 2, 4, & 6, & p. 20: #10