Finding the Fourth Proportional to 1,315.55, 1,815.50 and 756.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,315.55 : 1,815.50 = 756.15 : x
2. Step 2: Convert to fraction form
   1,315.55/1,815.50 = 756.15/x
3. Step 3: Cross multiply
   1,315.55x = 1,815.50 × 756.15
4. Step 4: Simplify right side
   1,315.55x = 1,372,790.33
5. Step 5: Solve for x
   x = 1,372,790.33/1,315.55
6. Step 6: Final answer
   x = 1,043.51