Finding the Third Proportional to 78,724 and 123,139.50

Step by Step Solution

1. Step 1: Write the proportion equation
   78,724 : 123,139.50 = 123,139.50 : x
2. Step 2: Convert to fraction form
   78,724/123,139.50 = 123,139.50/x
3. Step 3: Cross multiply
   78,724x = 123,139.50 × 123,139.50
4. Step 4: Simplify right side
   78,724x = 15,163,336,460.25
5. Step 5: Solve for x
   x = 15,163,336,460.25/78,724
6. Step 6: Final answer
   x = 192,613.90