Chapter 8 Section 2

Chapter 8 Section 2 - 8.2 Measures of Central Tendency In...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
    8.2 Measures of Central Tendency In this section, we will study three measures of central  tendency: the mean, the median and the mode. Each of  these values determines the “center” or middle of a set of  data. 
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
    Measures of Center Mean Most common Sum of the numbers divided by number of numbers Notation:   Example: The salary of 5 employees in thousands) is:  14, 17, 21, 18, 15 Find the mean: Sum = (14 + 17+21+18+15)=85 Divide 85 by 5 = 17. Thus, the average salary is 17,000 dollars. = = 1 n i i X X n
Background image of page 2
    The Mean as Center of Gravity  We will represent each data value on a “teeter-totter”. The  teeter-totter serves as number line.  You can think of each point's deviation from the mean as the  influence the point exerts on the tilt of the teeter totter. Positive  values push down on the right side; negative values push down  on the left side. The farther a point is from the fulcrum, the  more influence it has. Note that the mean deviation of the scores from the mean is  always zero. That is why the teeter totter is in balance when the  fulcrum is at the mean. This makes the mean the  center of  gravity for all the data points. 
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
    Data balances at 17. Sum of the deviations from mean equals zero. (-3 + -2 + 0 + 1 + 4 = 0 ) .  
Background image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/27/2008 for the course MATH 150 taught by Professor Unk during the Winter '07 term at San Jacinto.

Page1 / 13

Chapter 8 Section 2 - 8.2 Measures of Central Tendency In...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online