Finding the Fourth Proportional to 138,196.50, 207,286.52 and 81,302.37

Step by Step Solution

1. Step 1: Write the proportion equation
   138,196.50 : 207,286.52 = 81,302.37 : x
2. Step 2: Convert to fraction form
   138,196.50/207,286.52 = 81,302.37/x
3. Step 3: Cross multiply
   138,196.50x = 207,286.52 × 81,302.37
4. Step 4: Simplify right side
   138,196.50x = 16,852,884,938.54
5. Step 5: Solve for x
   x = 16,852,884,938.54/138,196.50
6. Step 6: Final answer
   x = 121,948.71