Finding the Fourth Proportional to 1,315.10, 1,815.24 and 783.98

Step by Step Solution

1. Step 1: Write the proportion equation
   1,315.10 : 1,815.24 = 783.98 : x
2. Step 2: Convert to fraction form
   1,315.10/1,815.24 = 783.98/x
3. Step 3: Cross multiply
   1,315.10x = 1,815.24 × 783.98
4. Step 4: Simplify right side
   1,315.10x = 1,423,111.86
5. Step 5: Solve for x
   x = 1,423,111.86/1,315.10
6. Step 6: Final answer
   x = 1,082.13