Finding the Fourth Proportional to 91,728.10, 137,592.15 and 91,728.10

Step by Step Solution

1. Step 1: Write the proportion equation
   91,728.10 : 137,592.15 = 91,728.10 : x
2. Step 2: Convert to fraction form
   91,728.10/137,592.15 = 91,728.10/x
3. Step 3: Cross multiply
   91,728.10x = 137,592.15 × 91,728.10
4. Step 4: Simplify right side
   91,728.10x = 12,621,066,494.42
5. Step 5: Solve for x
   x = 12,621,066,494.42/91,728.10
6. Step 6: Final answer
   x = 137,592.15