Finding the Fourth Proportional to 1,393.54, 1,922.16 and 869.86

Step by Step Solution

1. Step 1: Write the proportion equation
   1,393.54 : 1,922.16 = 869.86 : x
2. Step 2: Convert to fraction form
   1,393.54/1,922.16 = 869.86/x
3. Step 3: Cross multiply
   1,393.54x = 1,922.16 × 869.86
4. Step 4: Simplify right side
   1,393.54x = 1,672,010.10
5. Step 5: Solve for x
   x = 1,672,010.10/1,393.54
6. Step 6: Final answer
   x = 1,199.83