Finding the Fourth Proportional to 91,141.78, 136,711.85 and 28,812.30

Step by Step Solution

1. Step 1: Write the proportion equation
   91,141.78 : 136,711.85 = 28,812.30 : x
2. Step 2: Convert to fraction form
   91,141.78/136,711.85 = 28,812.30/x
3. Step 3: Cross multiply
   91,141.78x = 136,711.85 × 28,812.30
4. Step 4: Simplify right side
   91,141.78x = 3,938,982,835.76
5. Step 5: Solve for x
   x = 3,938,982,835.76/91,141.78
6. Step 6: Final answer
   x = 43,218.19