Sally went to the store and purchased 3 skirts, 4 dresses and 6 shirts. Anna went to the store and purchased 3 skirts, 3 dresses and 3 shirts. Each skirt costs $29, each dress cost $26, and each shirt costs $9. a) Write a 2 x 3 matrix summarizing the purchases made by Sally and Anna. (Keep the order of information). b) Write a 3 x 1 matrix summarizing the cost (in dollars) of the items. (Keep the order of information). c) Use matrix multiplication to find a 2 x 1 matrix summarizing the total amount (in dollars) spent by Sally and Anna.