Finding the Fourth Proportional to 1,339.31, 1,848.35 and 815.45

Step by Step Solution

1. Step 1: Write the proportion equation
   1,339.31 : 1,848.35 = 815.45 : x
2. Step 2: Convert to fraction form
   1,339.31/1,848.35 = 815.45/x
3. Step 3: Cross multiply
   1,339.31x = 1,848.35 × 815.45
4. Step 4: Simplify right side
   1,339.31x = 1,507,229.80
5. Step 5: Solve for x
   x = 1,507,229.80/1,339.31
6. Step 6: Final answer
   x = 1,125.38