Finding the Fourth Proportional to 1,315.08, 1,814.78 and 717.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,315.08 : 1,814.78 = 717.57 : x
2. Step 2: Convert to fraction form
   1,315.08/1,814.78 = 717.57/x
3. Step 3: Cross multiply
   1,315.08x = 1,814.78 × 717.57
4. Step 4: Simplify right side
   1,315.08x = 1,302,233.48
5. Step 5: Solve for x
   x = 1,302,233.48/1,315.08
6. Step 6: Final answer
   x = 990.23