1. Answer the following questions for the given dataset dd. data dd; input subject group 35 year salary : comma7. @@; cards; 1 a 2 53,900 2 b 2 37,400 3 a 1 49,500 4 C 2 43,900 5 b 3 38,400 6 a 3 39,500 7 a 3 53,600 8 b 2 37,700 9 c 1 49,900 10 C 2 43,300 11 b 3 57,400 12 b 3 39,500 13 b 1 33,900 14 a 2 41,400 15 c 2 49,500 16 C 1 43,900 17 b 1 39,400 18 a 3 39,900 19 a 2 53,600 20 a 2 37,700 21 c 3 42,900 22 C 2 43,300 23 b 1 57,400 24 C 3 69,500 25 C 2 33,900 26 a 2 35,300 27 a 2 47,500 28 C 2 43,900 29 b 3 38,400 30 a 1 32,500 31 a 3 53,600 32 b 2 37,700 33 C 1 41,600 34 C 2 43,300 35 b 3 57,400 36 b 3 39,500 37 b 2 33,900 38 a 2 41,400 39 C 2 79,500 40 C 1 43,900 41 C 1 29,500 42 a 3 39,900 43 a 2 53,600 44 a 2 37,500 45 C 3 42,900 46 C 2 43,300 47 b 1 47,400 48 c 3 59,500 , run; (1) Find the average salary for each group in each year. (2) Find the average, minimum and maximum salary in group b. (3) Find the average, minimum and maximum salary in each year