Finding the Fourth Proportional to 1,520.90, 2,098.89 and 857.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,520.90 : 2,098.89 = 857.72 : x
2. Step 2: Convert to fraction form
   1,520.90/2,098.89 = 857.72/x
3. Step 3: Cross multiply
   1,520.90x = 2,098.89 × 857.72
4. Step 4: Simplify right side
   1,520.90x = 1,800,259.93
5. Step 5: Solve for x
   x = 1,800,259.93/1,520.90
6. Step 6: Final answer
   x = 1,183.68