Finding the Fourth Proportional to 1,392.37, 1,920.32 and 861.01

Step by Step Solution

1. Step 1: Write the proportion equation
   1,392.37 : 1,920.32 = 861.01 : x
2. Step 2: Convert to fraction form
   1,392.37/1,920.32 = 861.01/x
3. Step 3: Cross multiply
   1,392.37x = 1,920.32 × 861.01
4. Step 4: Simplify right side
   1,392.37x = 1,653,410.42
5. Step 5: Solve for x
   x = 1,653,410.42/1,392.37
6. Step 6: Final answer
   x = 1,187.48