Finding the Fourth Proportional to 91,599.21, 137,407.50 and 28,420.02

Step by Step Solution

1. Step 1: Write the proportion equation
   91,599.21 : 137,407.50 = 28,420.02 : x
2. Step 2: Convert to fraction form
   91,599.21/137,407.50 = 28,420.02/x
3. Step 3: Cross multiply
   91,599.21x = 137,407.50 × 28,420.02
4. Step 4: Simplify right side
   91,599.21x = 3,905,123,898.15
5. Step 5: Solve for x
   x = 3,905,123,898.15/91,599.21
6. Step 6: Final answer
   x = 42,632.72