Example 1: Alena knows that her morning cup of coffee is a discretionary expense. She pays $2.75 for a 9-oz cup and was wondering if that is a typical price. On Monday, she asked 6 of her friends what they paid for a 9 oz cup of coffee. Their costs per cup were $2.85, $2.15, $1.95, $3.00, $2.05 and $2.40 SIGMA NOTATION Example 2: Use the information on page 6 of your text to examine the list of coffee prices in Example 1 (above). Find the mean using sigma notation.​