Finding the Third Proportional to 287,229 and 438,619.50

Step by Step Solution

1. Step 1: Write the proportion equation
   287,229 : 438,619.50 = 438,619.50 : x
2. Step 2: Convert to fraction form
   287,229/438,619.50 = 438,619.50/x
3. Step 3: Cross multiply
   287,229x = 438,619.50 × 438,619.50
4. Step 4: Simplify right side
   287,229x = 192,387,065,780.25
5. Step 5: Solve for x
   x = 192,387,065,780.25/287,229
6. Step 6: Final answer
   x = 669,803.77