Finding the Fourth Proportional to 91,978.32, 126,931.18 and 51,689.72

Step by Step Solution

1. Step 1: Write the proportion equation
   91,978.32 : 126,931.18 = 51,689.72 : x
2. Step 2: Convert to fraction form
   91,978.32/126,931.18 = 51,689.72/x
3. Step 3: Cross multiply
   91,978.32x = 126,931.18 × 51,689.72
4. Step 4: Simplify right side
   91,978.32x = 6,561,037,153.47
5. Step 5: Solve for x
   x = 6,561,037,153.47/91,978.32
6. Step 6: Final answer
   x = 71,332.43