Q7. The birth weights, in kg, of 1500 babies are summarised in the table below. Weight (ke) Midpoint. xkg Frequency, f 0.0 - 10 0.50 10 - 20 1.50 6 20-2.5 2.25 60 2.5 - 3.0 280 3.0 - 3.5 125 820 3.5 -40 3.75 320 4.0 -50 4.50 10 5.0-60 3 [You may use 2 {x = 4841 and _fx2 = 15 889.5] (a) Write down the missing midpoints in the table above. (b) Calculate an estimate of the mean birth weight. c) Calculate an estimate of the standard deviation of the birth weight