Finding the Third Proportional to 391,691 and 528,484.50

Step by Step Solution

1. Step 1: Write the proportion equation
   391,691 : 528,484.50 = 528,484.50 : x
2. Step 2: Convert to fraction form
   391,691/528,484.50 = 528,484.50/x
3. Step 3: Cross multiply
   391,691x = 528,484.50 × 528,484.50
4. Step 4: Simplify right side
   391,691x = 279,295,866,740.25
5. Step 5: Solve for x
   x = 279,295,866,740.25/391,691
6. Step 6: Final answer
   x = 713,051.53