In designing new desks for an incoming class of 25 kindergarten girls, an important characteristic of the desks is that they must accommodate the sitting heights of those students. (The sitting height is the height of a seated student measured from the bottom of the feet to the top of the knee.) Kindergarten girls have normally distributed sitting heights with a mean of 61.2 cm and a standard deviation of 3.1 cm.
a. What percentage of individual kindergarten girls have sitting heights greater than 63 cm?
b. For randomly selected groups of 25 kindergarten girls, what percentage of the group means is greater than 63 cm?
c. Which result is more relevant for the design of the desks: the result from part a or part b? Why?