Q2. Answer the following two questions under the assumption of normal populations with equal vari- ances. (a) The following are the numbers of sales which a random sample of nine salesmen of industrial chemicals in California and a random sample of six salesmen of industrial chemicals in Oregon made over a fixed period of time: (California) , : 40, 46, 61, 38, 55, 63, 36, 60, 51 (Oregon) yi : 33, 62, 44, 54, 23, 42 Using s 5% level of significance, test whether or not California salesmen are more efficient in general. Write down the null and alternative hypothesis first. (b) Suppose that we wish to investigate whether males and females earn comparable wages in a cer- tain industry. Sample data show that 14 randomly surveyed males earn on the average $213.5 per week with a standard deviation of $16.5, while 18 randomly surveyed females earn on the average $194.1 per week with a standard deviation of $18.0. Let /] denote the average wage of males and /2 the average of females. Using a 5% level of significance, test the null hypothesis that /1 = /2 against the alternative that /1 > /2