In: Statistics and Probability
Assume that newborn girls have birth weights with a mean of 3021 grams and a standard deviation of 694 grams. A random sample of 100 newborn girls is obtained and they have a mean birth weight of 2963 grams. What is the probability of randomly selecting another 100 newborn girls and getting a mean birth weight that is 2963 grams or lower?
Solution :
Given that,
mean =
= 3021
standard deviation =
=694
n = 100
=3021
=
/
n = 694
100 = 69.4
P(
< 2963 )
P (
-
/
) < ( 2963- 3021 / 69.4)
P ( z < -58 / 69.4 )
P ( z < -0.83)
= 0.2033
Probability = 0.2033