Haemoglobin level of pregnant women follow a normal distribution. If 40 out of 1000 women and 200 of 1000 have haemoglobin less than 9 and 10 respectively.

Question

Find the mean and stand deviation?

Answer 1

Mean = ((40+800)*9+(960+200)*10)/2000 = 9.58
Standard deviation = sqrt((((9 - 9.58)^2)*(40+800) + ((10-9.58)^2)*(960+200)))/2000) = 0.49356 (approximate)
[Hint: Use 2X2 matrix, as in Fisher exact test]