Consider the data in the table below:

X1 X2 X3 X4 X5 X6 2 5 6 11 9 8

a. Enumerate the following expression:

X 6

t¼1 Xt ¼ ?

b. Enumerate the following expression:

X 5

t¼3 Xt ¼ ?

c. Enumerate the following expression:

X 6

t¼1 X2 t

¼ ?

d. Express the sum of these X values (3 + 6 + 9 + 12 + 15 + 18 + 21) using the sigma notation.

AppendixLO1