Era's total aircraft sales per year are represented by T= W+Z. Answer the following questions Q35 and Q36 ignoring your answer in Q34 and assuming that the correlation coefficient between W and Z is 0.60.

To calculate the expected total annual sales E(T) : a) you must assume independence between W and Z b) the correlation between W and Z must be perfect c) W and Z must be normally distributed d) no assumption is necessary e) W and Z must be highly correlated

The standard deviation of total sales (T) is (in units) : a) between 1020 and 1030 b) between 1070 and 1080 c) between 1080 and 1090 d) impossible to calculate because the correlation between W and Z is not perfect e) impossible to calculate because W and Z are not independent