Finding the Fourth Proportional to 105,872.32, 146,006.28 and 71,931.60

Step by Step Solution

1. Step 1: Write the proportion equation
   105,872.32 : 146,006.28 = 71,931.60 : x
2. Step 2: Convert to fraction form
   105,872.32/146,006.28 = 71,931.60/x
3. Step 3: Cross multiply
   105,872.32x = 146,006.28 × 71,931.60
4. Step 4: Simplify right side
   105,872.32x = 10,502,465,330.45
5. Step 5: Solve for x
   x = 10,502,465,330.45/105,872.32
6. Step 6: Final answer
   x = 99,199.35