Finding the Fourth Proportional to 1,401.38, 1,933.70 and 811.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,401.38 : 1,933.70 = 811.80 : x
2. Step 2: Convert to fraction form
   1,401.38/1,933.70 = 811.80/x
3. Step 3: Cross multiply
   1,401.38x = 1,933.70 × 811.80
4. Step 4: Simplify right side
   1,401.38x = 1,569,777.66
5. Step 5: Solve for x
   x = 1,569,777.66/1,401.38
6. Step 6: Final answer
   x = 1,120.17