Finding the Fourth Proportional to 129,368.72, 178,531.62 and 72,011

Step by Step Solution

1. Step 1: Write the proportion equation
   129,368.72 : 178,531.62 = 72,011 : x
2. Step 2: Convert to fraction form
   129,368.72/178,531.62 = 72,011/x
3. Step 3: Cross multiply
   129,368.72x = 178,531.62 × 72,011
4. Step 4: Simplify right side
   129,368.72x = 12,856,240,487.82
5. Step 5: Solve for x
   x = 12,856,240,487.82/129,368.72
6. Step 6: Final answer
   x = 99,376.73