Finding the Fourth Proportional to 139,899.12, 209,873.60 and 65,103.72

Step by Step Solution

1. Step 1: Write the proportion equation
   139,899.12 : 209,873.60 = 65,103.72 : x
2. Step 2: Convert to fraction form
   139,899.12/209,873.60 = 65,103.72/x
3. Step 3: Cross multiply
   139,899.12x = 209,873.60 × 65,103.72
4. Step 4: Simplify right side
   139,899.12x = 13,663,551,221.39
5. Step 5: Solve for x
   x = 13,663,551,221.39/139,899.12
6. Step 6: Final answer
   x = 97,667.17