1. Question
A family of statisticians is trying to decide if they can afford for their child to play youth
baseball. The cost of joining a team is normally distributed with a mean of $750and a
standard deviation of $185. If a sample of 40teams is selected at random from the
population, select the expected mean and standard deviation of the sampling
distribution below.
Correct answer:
σx¯=$29.25
μx¯=$750
The standard deviation of the sampling distribution
σx¯=σn−−√=$18540−−√=$29.25
When the distribution is normal the mean of the sampling distribution is equal to the
mean of the population μx¯=μ=$750.
Question
A cupcake baker is planning a supplies order and needs to know how much flour he
needs. He knows that his recipes use an average of 100grams of flour, normally
distributed, with a population standard deviation of 15grams. If he is consulting a
sample size of 30recipes, select the mean and standard deviation of the sampling
distribution to help him order his supplies from the options below.
σx¯=2.74grams
μx¯=100grams
The standard deviation of the sampling distribution is
σx¯=σn−−√=1530−−√=2.74 grams