QUESTION 3 Six different machines are being considered for use in manufacturing rubber seals. The machines are being compared to the tensile strength of the product. A random sample of four seals from each machine is used to determine whether the mean tensile strength varies from machine to machine. The following are the tensile strength measurements in kilograms per square centimetre x10' Machine 1 2 3 4 5 17.5 6 16.4 20.3 14.6 17.5 18.3 16.9 19.3 15.7 16.7 19.3 15.8 16.3 17.7 17.8 21.8 16.5 17.5 18.6 15.4 19.9 18.9 21.5 21.1 a) Use Microsoft Excel to generate the Summary output for the data. (4 marks) b) From the summary output. Test whether the mean tensile strength varies from machine to machine. Use a=0.05. (7 marks)