Chapter 3 supplementary exercises

• Supplementary Exercise 3.1

  Refer to exercise 3.5. Suppose that the surprisingly low frequency of 2 in the 120 - 129 bin is correct, so that the total number of cables is 101. A possible explanation for only 2 cables is that the cables are hand-brake cables for cars from two suppliers, and that one supplier, who supplied a smaller proportion of the cables in the sample, produces cables with a higher yield.
  With n = 101 and a frequency of 2 in the 120 - 129 bin.
  1. Draw a histogram ensuring that the total area is 1.
  2. Draw a cumulative frequency polygon of the data.
  3. Calculate the approximate median, lower quartile, upper quartile, and inter-quartile range.
  4. Calculate an approximate mean and standard deviation of the sample yields from the grouped data, with n = 101 and 2 in the 120 - 129 bin.
     Compare your answers with those obtained using the data in Exercise 3.5 (n = 120 and a frequency of 21 in the 120 - 129 bin.)