Finding the Fourth Proportional to 1,148,499.45, 1,722,906.78 and 390,137.35

Step by Step Solution

1. Step 1: Write the proportion equation
   1,148,499.45 : 1,722,906.78 = 390,137.35 : x
2. Step 2: Convert to fraction form
   1,148,499.45/1,722,906.78 = 390,137.35/x
3. Step 3: Cross multiply
   1,148,499.45x = 1,722,906.78 × 390,137.35
4. Step 4: Simplify right side
   1,148,499.45x = 672,170,285,446.23
5. Step 5: Solve for x
   x = 672,170,285,446.23/1,148,499.45
6. Step 6: Final answer
   x = 585,259.56