**Practice # 3**

Create a function that calculates the average for a person with 4 classes.

**Practice #4**

Return the total cost of a purchase given the price of $35 and tax rate of 0.11.

Review: cost = price *(1+ tax)

**Practice # 5**

Create a function that converts a height in inches into feet and inches. 1 foot = 12 inches For example: 70 inches = 5 feet 10 inches Hint: Use the operators for long division.

**Practice # 6**

Create a function that calculates the perimeter of a square, given the length of the sides.