Finding the Fourth Proportional to 1,388.28, 1,915.76 and 758.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.28 : 1,915.76 = 758.81 : x
2. Step 2: Convert to fraction form
   1,388.28/1,915.76 = 758.81/x
3. Step 3: Cross multiply
   1,388.28x = 1,915.76 × 758.81
4. Step 4: Simplify right side
   1,388.28x = 1,453,684.47
5. Step 5: Solve for x
   x = 1,453,684.47/1,388.28
6. Step 6: Final answer
   x = 1,047.11