Finding the Fourth Proportional to 1,388.04, 1,915.83 and 863.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.04 : 1,915.83 = 863.88 : x
2. Step 2: Convert to fraction form
   1,388.04/1,915.83 = 863.88/x
3. Step 3: Cross multiply
   1,388.04x = 1,915.83 × 863.88
4. Step 4: Simplify right side
   1,388.04x = 1,655,047.22
5. Step 5: Solve for x
   x = 1,655,047.22/1,388.04
6. Step 6: Final answer
   x = 1,192.36