The total bill for the Cunningham family was $29.26.
Explanation:
Step 1; First we total up the cost of the food alone. Mr. Cunningham spent $7.50, Mrs. Cunningham spent $6.25, the 2 children spent $4.99 each which equals $9.98 for both. So the total of the food alone was $23.73.
Step 2; The sales tax rate was 7.25% of the $23.73. So we multiply 0.0725 (7.25%) with the $23.73 which equals $1.72. So the total bill was for $23.73 + $1.72 which equals $25.45.
Step 3; The Cunningham family left a 15% tip. This was 15% of the toal bill which was $25.45. So we multiply 0.15 (15%) with $25.45 which equals $3.81. So the total bill was food cost + service tax + tips which is $23.73 + $1.72 + $3.81 = $29.26