Finding the Fourth Proportional to 102.72, 141.76 and 56.10

Step by Step Solution

1. Step 1: Write the proportion equation
   102.72 : 141.76 = 56.10 : x
2. Step 2: Convert to fraction form
   102.72/141.76 = 56.10/x
3. Step 3: Cross multiply
   102.72x = 141.76 × 56.10
4. Step 4: Simplify right side
   102.72x = 7,952.74
5. Step 5: Solve for x
   x = 7,952.74/102.72
6. Step 6: Final answer
   x = 77.42