Finding the Fourth Proportional to 1,388.15, 1,915.65 and 758.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.15 : 1,915.65 = 758.69 : x
2. Step 2: Convert to fraction form
   1,388.15/1,915.65 = 758.69/x
3. Step 3: Cross multiply
   1,388.15x = 1,915.65 × 758.69
4. Step 4: Simplify right side
   1,388.15x = 1,453,374.92
5. Step 5: Solve for x
   x = 1,453,374.92/1,388.15
6. Step 6: Final answer
   x = 1,046.99