Monthly Motorcycle Casualties. The Scottish Executive, Analytical Services Division Transport Statistics, compiles data on motorcycle casualties. During one year, monthly casualties resulting from motorcycle accidents in Scotland for built-up roads and non–

built-up roads were as follows.

Month Built-up Non–built-up January 25 16 February 38 9 March 38 26 April 56 48 May 61 73 June 52 72 July 50 91 August 90 69 September 67 71 October 51 28 November 64 19 December 40 12

a. Without doing any calculations, make an educated guess at which of the two data sets, built-up or non–built-up, has the greater variation.

b. Find the range and sample standard deviation of each of the two data sets. Compare your results here to the educated guess that you made in part (a).