The level of rainwater in a tank was recorded weekly for 20 weeks, as number of cm below the maximum capacity level. In other words, yi​=100(1.2−xi​)i=1,2,…,20 where xi​ is the height of rainwater in m and 1.2 m is the maximum capacity height of the tank. The sample mean and sample standard deviation of y are 74.4 cm and 16.2 cm respectively. What are the sample mean and sample standard deviation of x ? (a) mean =0.744 m, standard deviation =1.048 m, (b) mean =0.456 m, standard deviation =1.048 m, (c) mean =0.456 m, standard deviation =0.162 m, (d) mean =0.744 m, standard deviation =0.162 m, (e) mean =−0.744 m, standard deviation =−0.162 m.