Finding the Fourth Proportional to 102.77, 141.83 and 56.15

Step by Step Solution

1. Step 1: Write the proportion equation
   102.77 : 141.83 = 56.15 : x
2. Step 2: Convert to fraction form
   102.77/141.83 = 56.15/x
3. Step 3: Cross multiply
   102.77x = 141.83 × 56.15
4. Step 4: Simplify right side
   102.77x = 7,962.76
5. Step 5: Solve for x
   x = 7,962.76/102.77
6. Step 6: Final answer
   x = 77.48