Finding the Third Proportional to 287,820 and 402,588

Step by Step Solution

1. Step 1: Write the proportion equation
   287,820 : 402,588 = 402,588 : x
2. Step 2: Convert to fraction form
   287,820/402,588 = 402,588/x
3. Step 3: Cross multiply
   287,820x = 402,588 × 402,588
4. Step 4: Simplify right side
   287,820x = 162,077,097,744
5. Step 5: Solve for x
   x = 162,077,097,744/287,820
6. Step 6: Final answer
   x = 563,119.65