Read the information in the attachment below and answer the questions therein.

(i) Two inspectors carry out property valuations for an estate agency. Over a particular week they each go out to similar properties. The table below shows their valuations (in f000s): A 102 98 93 86 92 94 89 97 B 86 88 92 95 98 97 94 92 91 (a) Make an informative plot of these data. (b) Comment on an assumption of equal variance for the two underlying populations. (c) With the equal variance assumption of (b), calculate a 95% confidence interval for this common variance. (d) Calculate a 95% confidence interval for the mean difference between the valuations by A and B. and comment briefly on the result. (ii) The estate agency employing the inspectors decides to test their valuations by sending them each to the same set of eight houses, independently and without knowledge that the other is going. The resulting valuations (in (000s) follow: Property 1 2 3 4 5 6 7 8 A 94 98 102 132 118 121 106 123 B 92 96 111 129 111 122 101 118 (a) Make an informative plot of these data. (b) Calculate a 90% confidence interval for the mean difference between valuations by A and B, and comment briefly on the result