Finding the Fourth Proportional to 1,399.35, 2,100.55 and 814.99

Step by Step Solution

1. Step 1: Write the proportion equation
   1,399.35 : 2,100.55 = 814.99 : x
2. Step 2: Convert to fraction form
   1,399.35/2,100.55 = 814.99/x
3. Step 3: Cross multiply
   1,399.35x = 2,100.55 × 814.99
4. Step 4: Simplify right side
   1,399.35x = 1,711,927.24
5. Step 5: Solve for x
   x = 1,711,927.24/1,399.35
6. Step 6: Final answer
   x = 1,223.37