Finding the Fourth Proportional to 1,431.02, 2,147.34 and 815.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,431.02 : 2,147.34 = 815.42 : x
2. Step 2: Convert to fraction form
   1,431.02/2,147.34 = 815.42/x
3. Step 3: Cross multiply
   1,431.02x = 2,147.34 × 815.42
4. Step 4: Simplify right side
   1,431.02x = 1,750,983.98
5. Step 5: Solve for x
   x = 1,750,983.98/1,431.02
6. Step 6: Final answer
   x = 1,223.59