A school has four classes with 10 20 30 and 40 students. Their pass percentages are 20 percent 30 percent 60 percent and 100 percent. Find the pass percentage of the entire school

Step 1 Compute passed students. Two plus six plus eighteen plus forty equals sixty six. Step 2 Total students equal one hundred. Step 3 Overall pass percentage equals sixty six percent. Weighted averages are essential. Always multiply each class by its rate then sum before dividing by total strength.