The birth weight of full-term babies was found to follow a normal distribution with a mean of 3500grams, and standard deviation of 600grams.

Question

A) What is probability that the birth weight is less than 3000 grams.
= P(X<3000) Correct?
B) probability that birth weight exceeds 4000grams P(X>4000) Correct?
C) birth weight between 3000 and 4000
P(3000<X>4000) Correct?

D) This one confuses me
birth weight less than 2000 OR greater than 5000????

Answer 1

http://davidmlane.com/hyperstat/z_table.html

D -- add the percent < 2000 to the percent > 5000

Answer 2

LOL or subtract the percent between 2000 and 5000 from 100 :)

Answer 3

Correct as far as you went, but what are the probabilities?

Z = (score-mean)/SD

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability
related to the Z scores.

D) Either-or probabilities are found by adding the individual probabilities.

Answer 4

When I say percent I men probability = percent/100

Answer 5

The z table is at that David Lane link