Outliers from raw data

Questions where raw data values are provided and the student must calculate quartiles and IQR from the data before applying the outlier rule.

1 questions

Edexcel S1 2003 June Q6
6. The number of bags of potato crisps sold per day in a bar was recorded over a two-week period. The results are shown below. $$20,15,10,30,33,40,5,11,13,20,25,42,31,17$$
  1. Calculate the mean of these data.
  2. Draw a stem and leaf diagram to represent these data.
  3. Find the median and the quartiles of these data. An outlier is an observation that falls either \(1.5 \times\) (interquartile range) above the upper quartile or \(1.5 \times\) (interquartile range) below the lower quartile.
  4. Determine whether or not any items of data are outliers.
  5. On graph paper draw a box plot to represent these data. Show your scale clearly.
  6. Comment on the skewness of the distribution of bags of crisps sold per day. Justify your answer.