Finding the Fourth Proportional to 1,309.61, 1,962.59 and 724.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,309.61 : 1,962.59 = 724.88 : x
2. Step 2: Convert to fraction form
   1,309.61/1,962.59 = 724.88/x
3. Step 3: Cross multiply
   1,309.61x = 1,962.59 × 724.88
4. Step 4: Simplify right side
   1,309.61x = 1,422,643.52
5. Step 5: Solve for x
   x = 1,422,643.52/1,309.61
6. Step 6: Final answer
   x = 1,086.31