Finding the Fourth Proportional to 1,387.89, 1,915.71 and 798.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,387.89 : 1,915.71 = 798.82 : x
2. Step 2: Convert to fraction form
   1,387.89/1,915.71 = 798.82/x
3. Step 3: Cross multiply
   1,387.89x = 1,915.71 × 798.82
4. Step 4: Simplify right side
   1,387.89x = 1,530,307.46
5. Step 5: Solve for x
   x = 1,530,307.46/1,387.89
6. Step 6: Final answer
   x = 1,102.61