Finding the Third Proportional to 391,699.50 and 528,498

Step by Step Solution

1. Step 1: Write the proportion equation
   391,699.50 : 528,498 = 528,498 : x
2. Step 2: Convert to fraction form
   391,699.50/528,498 = 528,498/x
3. Step 3: Cross multiply
   391,699.50x = 528,498 × 528,498
4. Step 4: Simplify right side
   391,699.50x = 279,310,136,004
5. Step 5: Solve for x
   x = 279,310,136,004/391,699.50
6. Step 6: Final answer
   x = 713,072.49