Finding the Third Proportional to 398,898 and 864,256.50

Step by Step Solution

1. Step 1: Write the proportion equation
   398,898 : 864,256.50 = 864,256.50 : x
2. Step 2: Convert to fraction form
   398,898/864,256.50 = 864,256.50/x
3. Step 3: Cross multiply
   398,898x = 864,256.50 × 864,256.50
4. Step 4: Simplify right side
   398,898x = 746,939,297,792.25
5. Step 5: Solve for x
   x = 746,939,297,792.25/398,898
6. Step 6: Final answer
   x = 1,872,507.00