The numbers below represents heights (in feet) of 3-year old elm trees, where leaves represent fractional parts of each value.

Stems Leaves
5 1,8
6 1,2,4,7,8,9
7 0,2,3,3,4,5
8 1,1,2,3,5,6,6,7,7,9,9
9 0,1,3,4

a) Find the five number summary for the given set of data.
b) Produce a box and whisker plot for the data.
c) Assuming that the heights of 3-year old elm trees are normally distributed find a 95% confidence interval for the mean height of 3-year old elm trees.