Finding the Fourth Proportional to 1,085.64, 1,498.20 and 619.86

Step by Step Solution

1. Step 1: Write the proportion equation
   1,085.64 : 1,498.20 = 619.86 : x
2. Step 2: Convert to fraction form
   1,085.64/1,498.20 = 619.86/x
3. Step 3: Cross multiply
   1,085.64x = 1,498.20 × 619.86
4. Step 4: Simplify right side
   1,085.64x = 928,674.25
5. Step 5: Solve for x
   x = 928,674.25/1,085.64
6. Step 6: Final answer
   x = 855.42