Finding the Fourth Proportional to 1,388.07, 1,915.61 and 798.71

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.07 : 1,915.61 = 798.71 : x
2. Step 2: Convert to fraction form
   1,388.07/1,915.61 = 798.71/x
3. Step 3: Cross multiply
   1,388.07x = 1,915.61 × 798.71
4. Step 4: Simplify right side
   1,388.07x = 1,530,003.29
5. Step 5: Solve for x
   x = 1,530,003.29/1,388.07
6. Step 6: Final answer
   x = 1,102.25