Finding the Fourth Proportional to 1,401.81, 2,098.65 and 815.03

Step by Step Solution

1. Step 1: Write the proportion equation
   1,401.81 : 2,098.65 = 815.03 : x
2. Step 2: Convert to fraction form
   1,401.81/2,098.65 = 815.03/x
3. Step 3: Cross multiply
   1,401.81x = 2,098.65 × 815.03
4. Step 4: Simplify right side
   1,401.81x = 1,710,452.66
5. Step 5: Solve for x
   x = 1,710,452.66/1,401.81
6. Step 6: Final answer
   x = 1,220.17