Given the stem-and-leaf plot below, answer the following questions:
Stem-and-Leaf Display: Age
Strem   Leaves
1     78
2     015
3     6
4     555
5       56
6     35
7
8     5
9     8
a) What is the number of observations?
b) What is the range of the data?
c) What is the median?
d) Calculate the mean
e) What is the mode?