Finding the Fourth Proportional to 128,736.56, 177,663.76 and 72,151.58

Step by Step Solution

1. Step 1: Write the proportion equation
   128,736.56 : 177,663.76 = 72,151.58 : x
2. Step 2: Convert to fraction form
   128,736.56/177,663.76 = 72,151.58/x
3. Step 3: Cross multiply
   128,736.56x = 177,663.76 × 72,151.58
4. Step 4: Simplify right side
   128,736.56x = 12,818,721,256.52
5. Step 5: Solve for x
   x = 12,818,721,256.52/128,736.56
6. Step 6: Final answer
   x = 99,573.28