Finding the Fourth Proportional to 1,386.17, 1,912.90 and 756.71

Step by Step Solution

1. Step 1: Write the proportion equation
   1,386.17 : 1,912.90 = 756.71 : x
2. Step 2: Convert to fraction form
   1,386.17/1,912.90 = 756.71/x
3. Step 3: Cross multiply
   1,386.17x = 1,912.90 × 756.71
4. Step 4: Simplify right side
   1,386.17x = 1,447,510.56
5. Step 5: Solve for x
   x = 1,447,510.56/1,386.17
6. Step 6: Final answer
   x = 1,044.25