descriptive statistics

• what are the 3 measures of central tendency

  mean, median, mode
• what is the mean

  add up all results and then divide them by the number of results there were. the average of the group
• advantages of the mean

  you dont have to put the data in order, mean is a very descriptive value
• disadvantages of the mean

  may end up with a decimal number. can be skewed due to an outlier
• what is the median

  order all results from smallest to largest and find the middle number
• advantages of the median

  not affected by one outlier, combined with mean it can be a very descriptive tool
• disadvantages of the median

  must put the number in order of smallest to largest, the way you find the mean differs depending on how many numbers in group
• what is the mode

  the most common
• advantages of the mode

  you dont have to put the data in order, no calculations necessary
• disadvantages of the mode

  is possible to have no mode, one mode or many, not great description of data