Finding the Third Proportional to 398,128 and 866,236.50

Step by Step Solution

1. Step 1: Write the proportion equation
   398,128 : 866,236.50 = 866,236.50 : x
2. Step 2: Convert to fraction form
   398,128/866,236.50 = 866,236.50/x
3. Step 3: Cross multiply
   398,128x = 866,236.50 × 866,236.50
4. Step 4: Simplify right side
   398,128x = 750,365,673,932.25
5. Step 5: Solve for x
   x = 750,365,673,932.25/398,128
6. Step 6: Final answer
   x = 1,884,734.74