Finding the Fourth Proportional to 153,715.59, 212,128.71 and 85,736.88

Step by Step Solution

1. Step 1: Write the proportion equation
   153,715.59 : 212,128.71 = 85,736.88 : x
2. Step 2: Convert to fraction form
   153,715.59/212,128.71 = 85,736.88/x
3. Step 3: Cross multiply
   153,715.59x = 212,128.71 × 85,736.88
4. Step 4: Simplify right side
   153,715.59x = 18,187,253,753.82
5. Step 5: Solve for x
   x = 18,187,253,753.82/153,715.59
6. Step 6: Final answer
   x = 118,317.56