Question

Pediatricians have been able to determine that the distribution of birth weights for boys is approximately normal with mean 3494 grams and standard deviation 603 grams. They have also determined that the distribution of birth weights for girls is apporximately normal with mean 3266 grams and standard deviation 570 grams.

1. There is a baby boy named Brock who weighed 3232 grams at birth. There is a baby girl named Brittney who weighed 3137 grams. Who has a relatively hugher birth weight: Brittney or Brock? Show all work and calculations. (Hint: use Z-scores)

Answer 1

Solution :

Given that ,

mean = = 3494 ( Brock)

standard deviation =  = 603

x = 3232

Using z-score formula,

z = x - /   

z = 3232 - 3494 / 603

z = -0.43 ( Brock)

mean = = 3266 ( Brittney)

standard deviation =  = 570

x = 3137

Using z-score formula,

z = x - /   

z = 3137 - 3266 / 570

z = -0.23 ( Brittney)

Brittney has a relatively hugher birth weight