Finding the Fourth Proportional to 1,078.80, 1,617.72 and 309.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,078.80 : 1,617.72 = 309.12 : x
2. Step 2: Convert to fraction form
   1,078.80/1,617.72 = 309.12/x
3. Step 3: Cross multiply
   1,078.80x = 1,617.72 × 309.12
4. Step 4: Simplify right side
   1,078.80x = 500,069.61
5. Step 5: Solve for x
   x = 500,069.61/1,078.80
6. Step 6: Final answer
   x = 463.54