Finding the Fourth Proportional to 1,388.30, 1,915.91 and 798.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.30 : 1,915.91 = 798.83 : x
2. Step 2: Convert to fraction form
   1,388.30/1,915.91 = 798.83/x
3. Step 3: Cross multiply
   1,388.30x = 1,915.91 × 798.83
4. Step 4: Simplify right side
   1,388.30x = 1,530,486.39
5. Step 5: Solve for x
   x = 1,530,486.39/1,388.30
6. Step 6: Final answer
   x = 1,102.42