Finding the Third Proportional to 139,617 and 208,861.50

Step by Step Solution

1. Step 1: Write the proportion equation
   139,617 : 208,861.50 = 208,861.50 : x
2. Step 2: Convert to fraction form
   139,617/208,861.50 = 208,861.50/x
3. Step 3: Cross multiply
   139,617x = 208,861.50 × 208,861.50
4. Step 4: Simplify right side
   139,617x = 43,623,126,182.25
5. Step 5: Solve for x
   x = 43,623,126,182.25/139,617
6. Step 6: Final answer
   x = 312,448.53