Finding the Fourth Proportional to 1,393.86, 1,921.50 and 1,098.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,393.86 : 1,921.50 = 1,098.60 : x
2. Step 2: Convert to fraction form
   1,393.86/1,921.50 = 1,098.60/x
3. Step 3: Cross multiply
   1,393.86x = 1,921.50 × 1,098.60
4. Step 4: Simplify right side
   1,393.86x = 2,110,959.90
5. Step 5: Solve for x
   x = 2,110,959.90/1,393.86
6. Step 6: Final answer
   x = 1,514.47