Finding the Fourth Proportional to 1,079.61, 1,489.85 and 613.86

Step by Step Solution

1. Step 1: Write the proportion equation
   1,079.61 : 1,489.85 = 613.86 : x
2. Step 2: Convert to fraction form
   1,079.61/1,489.85 = 613.86/x
3. Step 3: Cross multiply
   1,079.61x = 1,489.85 × 613.86
4. Step 4: Simplify right side
   1,079.61x = 914,559.32
5. Step 5: Solve for x
   x = 914,559.32/1,079.61
6. Step 6: Final answer
   x = 847.12