Finding the Fourth Proportional to 1,085.79, 1,498.30 and 613.66

Step by Step Solution

1. Step 1: Write the proportion equation
   1,085.79 : 1,498.30 = 613.66 : x
2. Step 2: Convert to fraction form
   1,085.79/1,498.30 = 613.66/x
3. Step 3: Cross multiply
   1,085.79x = 1,498.30 × 613.66
4. Step 4: Simplify right side
   1,085.79x = 919,444.31
5. Step 5: Solve for x
   x = 919,444.31/1,085.79
6. Step 6: Final answer
   x = 846.80