chp 3 representation of data

• outlier is an extreme value that is 1.5 standard deviations from the mean
• frequency density= frequency/class width
• removing anomalies from data is known as cleaning data
• grouped continuous data can be represented in a histogram
• comparing data sets you can comment on:

  a measure of location

  a measure of spread
• common formula for finding outliers:

  • greater than Q3 +k(iqr)
  • less than Q1 - k(iqr)
• you can compare data using the:

  • mean and standard deviation
  • median and the iqr (for extreme values)