Finding the Fourth Proportional to 72.67, 100.28 and 56.42

Step by Step Solution

1. Step 1: Write the proportion equation
   72.67 : 100.28 = 56.42 : x
2. Step 2: Convert to fraction form
   72.67/100.28 = 56.42/x
3. Step 3: Cross multiply
   72.67x = 100.28 × 56.42
4. Step 4: Simplify right side
   72.67x = 5,657.70
5. Step 5: Solve for x
   x = 5,657.70/72.67
6. Step 6: Final answer
   x = 77.85