Mod 3

• Measures of Central Tendency


  A single value that describes a set of data by identifying the central position within the set of data
• Mean


  The most frequently used measure of central tendency; the mean is equal to the sum of all values in the data set divided by the number of values in the data set
• Properties of Mean


  • A set of data has only one mean
  • Mean can be applied for interval and ratio data
  • All values in the data set are included in computing the mean
  • The mean is very useful in comparing two or more data sets
  • Mean is affected by extreme small or large values on a data set (outliers)
• Mean for Ungrouped Data

  1. Sample Problem 1: Find the mean daily rate of employees

  2. Sample Problem 2: Find the population mean of the ages of middle management employees
• Mean for Grouped Data

  Sample Problem 3: Determine the mean of the frequency distribution of ages of people taking travel tours
• Median


  The midpoint of the data set
• Properties of Median


  • There is only one median for a set of data
  • The median is found by arranging the set of data from lowest to highest, and getting the value of the middle observation
  • Median is not affected by the extreme small or large values (outliers)
• Median for Ungrouped Data

  1. If the population/sample size is odd, the median is the middle rank

  2. If the population/sample size is even, the median is the average of the two middle ranked values
• Median for Grouped Data

  Sample Problem 5: Determine the median of the frequency distribution on the ages of people taking travel tours
• Mode


  The value in a data set that appears most frequently
• Properties of Mode


  • The mode is found by locating the most frequently occurring value
  • The mode is the easiest measure of central tendency to compute
  • There can be more than one mode or no mode in any given data set
  • Mode is not affected by the extreme small or large values (outliers)
• Mode


  Sample Problem 6: Find the mode of the total unit sales for PSP 2000
• Midrange


  The average of the lowest and highest value in a data set
• Properties of Midrange


  • The midrange is easy to compute
  • The midrange is unique
  • Midrange is affected by the extreme small or large values (outliers)
• Midrange


  Sample Problem 7: Find the midrange of the ages of middle management employees
• Measures of Central Tendency


  A single value that describes a set of data by identifying the central position within the set of data
• Mean


  The most frequently used measure of central tendency; the mean is equal to the sum of all values in the data set divided by the number of values in the data set
• Properties of Mean


  • A set of data has only one mean
  • Mean can be applied for interval and ratio data
  • All values in the data set are included in computing the mean
  • The mean is very useful in comparing two or more data sets
  • Mean is affected by extreme small or large values on a data set (outliers)
• Mean for Ungrouped Data

  1. Sample Problem 1: Find the mean daily rate of employees

  2. Sample Problem 2: Find the population mean age of middle management employees
• Mean for Grouped Data

  Sample Problem 3: Determine the mean age of people taking travel tours
• Median


  The midpoint of the data set
• Properties of Median


  • There is only one median for a set of data
  • The median is found by arranging the set of data from lowest to highest, and getting the value of the middle observation
  • Median is not affected by the extreme small or large values (outliers)
• Median for Ungrouped Data

  1. If the population/sample size is odd, the median is the middle rank

  2. If the population/sample size is even, the median is the average of the two middle ranked values
• Median for Grouped Data

  Sample Problem 5: Determine the median age of people taking travel tours
• Mode


  The value in a data set that appears most frequently
• Properties of Mode


  • The mode is found by locating the most frequently occurring value
  • The mode is the easiest measure of central tendency to compute
  • There can be more than one mode or no mode in any given data set
  • Mode is not affected by the extreme small or large values (outliers)
• Mode


  Sample Problem 6: Find the mode of total unit sales for PSP 2000
• Midrange


  The average of the lowest and highest value in a data set
• Properties of Midrange


  • The midrange is easy to compute
  • The midrange is unique
  • Midrange is affected by the extreme small or large values (outliers)
• Midrange


  Sample Problem 7: Find the midrange of the ages of middle management employees
• Measures of Central Tendency


  A single value that describes a set of data by identifying the central position within the set of data
• Mean


  The most frequently used measure of central tendency; the mean is equal to the sum of all values in the data set divided by the number of values in the data set
• Mean


  • A set of data has only one mean
  • Mean can be applied for interval and ratio data
  • All values in the data set are included in computing the mean
  • The mean is very useful in comparing two or more data sets
  • Mean is affected by extreme small or large values on a data set (outliers)
• Calculating Mean for Ungrouped Data

  1. Sample Problem 1: Find the mean daily rate of employees

  2. Sample Problem 2: Find the population mean age of middle management employees
• Calculating Mean for Grouped Data

  Sample Problem 3: Find the mean age of people taking travel tours
• Median


  The midpoint of the data set
• Median


  • There is only one median for a set of data
  • The median is found by arranging the set of data from lowest to highest, and getting the value of the middle observation
  • Median is not affected by the extreme small or large values (outliers)
• Calculating Median for Ungrouped Data

  Sample Problem 4: Find the median age of middle management employees
• Calculating Median for Grouped Data

  Sample Problem 5: Find the median age of people taking travel tours
• Mode


  The value in a data set that appears most frequently