Finding the Fourth Proportional to 1,401.20, 1,932.90 and 869.91

Step by Step Solution

1. Step 1: Write the proportion equation
   1,401.20 : 1,932.90 = 869.91 : x
2. Step 2: Convert to fraction form
   1,401.20/1,932.90 = 869.91/x
3. Step 3: Cross multiply
   1,401.20x = 1,932.90 × 869.91
4. Step 4: Simplify right side
   1,401.20x = 1,681,449.04
5. Step 5: Solve for x
   x = 1,681,449.04/1,401.20
6. Step 6: Final answer
   x = 1,200.01