Finding the Fourth Proportional to 1,315.72, 1,815.90 and 844.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,315.72 : 1,815.90 = 844.15 : x
2. Step 2: Convert to fraction form
   1,315.72/1,815.90 = 844.15/x
3. Step 3: Cross multiply
   1,315.72x = 1,815.90 × 844.15
4. Step 4: Simplify right side
   1,315.72x = 1,532,887.68
5. Step 5: Solve for x
   x = 1,532,887.68/1,315.72
6. Step 6: Final answer
   x = 1,165.06