Answer
(a) 6.875
(b) 5.375
(c) 5.9375
(d) M6
Work Step by Step
(a) R6 = 0.5(1.25+1+1.25+2+3.25+5) = 6.875
(b) L6 = 0.5(2+1.25+1+1.25+2+3.25) = 5.375
(c) M6 = 0.5(1.5625+1.0625+1.0625+1.5625+2.5625+4.0625) = 5.9375
(d) M6 has the best estimate.