Finding the Third Proportional to 580.78 and 898.31

Step by Step Solution

1. Step 1: Write the proportion equation
   580.78 : 898.31 = 898.31 : x
2. Step 2: Convert to fraction form
   580.78/898.31 = 898.31/x
3. Step 3: Cross multiply
   580.78x = 898.31 × 898.31
4. Step 4: Simplify right side
   580.78x = 806,965.35
5. Step 5: Solve for x
   x = 806,965.35/580.78
6. Step 6: Final answer
   x = 1,389.45