Finding the Fourth Proportional to 1,388.06, 1,915.58 and 798.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.06 : 1,915.58 = 798.60 : x
2. Step 2: Convert to fraction form
   1,388.06/1,915.58 = 798.60/x
3. Step 3: Cross multiply
   1,388.06x = 1,915.58 × 798.60
4. Step 4: Simplify right side
   1,388.06x = 1,529,772.61
5. Step 5: Solve for x
   x = 1,529,772.61/1,388.06
6. Step 6: Final answer
   x = 1,102.09