Suppose duration of human pregnancies are somewhat skewed with a mean of 262 days and a standard deviation of 15 days. Suppose a certain obstetrician is currently providing prenatal care to 40 pregnant women. Let bar-y represent the mean length of their pregnancies.
Is the distribution of sample means normal or not normal?
What is the value of sigma bar-y? (carry two decimals)
Suppose the obstetrician provided prenatal care to 45 pregnant women instead. How would this change the mean of the dirstibution of sample means? (smaller, larger or no change)
How would this change the standard deviation of sample means?