Question

Suppose medical records indicate that the length of newborn babies (in inches) is normally distributed with a mean of 20 and a standard deviation of 2.6. Find the probability that a given infant is longer than 20 inches. [? ]%

Answer 1

To find the probability we need to use the z score formula, given by:

`z=(x-\mu)/(\sigma)`

where x is the value we like, mu is the median and sigma is the standard deviation.

Then the z score is:

`z=(20-20)/(2.6)=0`

Then we have to look for the proability:

`P(z>0)=0.5`

Therefore the probability that a given infant is longer than 20 inches is 0.5 or 50%.