Finding the Fourth Proportional to 978,139.20, 1,370,328 and 978,139.20

Step by Step Solution

1. Step 1: Write the proportion equation
   978,139.20 : 1,370,328 = 978,139.20 : x
2. Step 2: Convert to fraction form
   978,139.20/1,370,328 = 978,139.20/x
3. Step 3: Cross multiply
   978,139.20x = 1,370,328 × 978,139.20
4. Step 4: Simplify right side
   978,139.20x = 1,340,371,533,657.60
5. Step 5: Solve for x
   x = 1,340,371,533,657.60/978,139.20
6. Step 6: Final answer
   x = 1,370,328