Select all the correct answers. ≥ 1/2x + 5 2x - y < 7 for the system above, which of the following are solutions? (-1,5) (-4,1) (-10,0) (10,13) (2,8) (2,-1)

Do one of the following, as appropriate: (a) find the critical value z subscript alpha divided by 2 , (b) find the critical value t subscript alpha divided by 2 . 99%; nequals 17; sigma is unknown; population appears to be normally distributed.