Finding the Third Proportional to 67,066.50 and 139,642.50

Step by Step Solution

1. Step 1: Write the proportion equation
   67,066.50 : 139,642.50 = 139,642.50 : x
2. Step 2: Convert to fraction form
   67,066.50/139,642.50 = 139,642.50/x
3. Step 3: Cross multiply
   67,066.50x = 139,642.50 × 139,642.50
4. Step 4: Simplify right side
   67,066.50x = 19,500,027,806.25
5. Step 5: Solve for x
   x = 19,500,027,806.25/67,066.50
6. Step 6: Final answer
   x = 290,756.60