Finding the Fourth Proportional to 1,386.47, 2,079.72 and 606.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,386.47 : 2,079.72 = 606.31 : x
2. Step 2: Convert to fraction form
   1,386.47/2,079.72 = 606.31/x
3. Step 3: Cross multiply
   1,386.47x = 2,079.72 × 606.31
4. Step 4: Simplify right side
   1,386.47x = 1,260,949.83
5. Step 5: Solve for x
   x = 1,260,949.83/1,386.47
6. Step 6: Final answer
   x = 909.47