Finding the Third Proportional to 260,217 and 402,142.50

Step by Step Solution

1. Step 1: Write the proportion equation
   260,217 : 402,142.50 = 402,142.50 : x
2. Step 2: Convert to fraction form
   260,217/402,142.50 = 402,142.50/x
3. Step 3: Cross multiply
   260,217x = 402,142.50 × 402,142.50
4. Step 4: Simplify right side
   260,217x = 161,718,590,306.25
5. Step 5: Solve for x
   x = 161,718,590,306.25/260,217
6. Step 6: Final answer
   x = 621,475.88