The weights of newborn babies are distributed normally, with a mean of approximately 95 oz and a standard deviation of 20 oz. If a newborn baby is selected at random, what is the probability that the baby weighs more than 35 oz?
To find the probability that a randomly selected newborn baby weighs more than 35 oz, we need to use the standard normal distribution.
First, we calculate the z-score (standard score) for 35 oz using the formula: z = (x - μ) / σ, where x is the given weight, μ is the mean, and σ is the standard deviation.
z = (35 - 95) / 20
z = -60 / 20
z = -3
Next, we look up the z-score in the standard normal distribution table or use a calculator to find the area (probability) to the left of the z-score.
In this case, the area to the left of z = -3 is approximately 0.0013.
Since we want the probability that the baby weighs more than 35 oz, we subtract the area to the left from 1.
P(Weight > 35 oz) = 1 - 0.0013
P(Weight > 35 oz) ≈ 0.9987
Therefore, the probability that a randomly selected newborn baby weighs more than 35 oz is approximately 0.9987 or 99.87%.
You will need this webpage for your kind of problem
http://davidmlane.com/normal.html