Finding the Third Proportional to 578.81 and 898.59

Step by Step Solution

1. Step 1: Write the proportion equation
   578.81 : 898.59 = 898.59 : x
2. Step 2: Convert to fraction form
   578.81/898.59 = 898.59/x
3. Step 3: Cross multiply
   578.81x = 898.59 × 898.59
4. Step 4: Simplify right side
   578.81x = 807,470.73
5. Step 5: Solve for x
   x = 807,470.73/578.81
6. Step 6: Final answer
   x = 1,395.05