Finding the Fourth Proportional to 1,387.55, 1,914.88 and 798.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,387.55 : 1,914.88 = 798.28 : x
2. Step 2: Convert to fraction form
   1,387.55/1,914.88 = 798.28/x
3. Step 3: Cross multiply
   1,387.55x = 1,914.88 × 798.28
4. Step 4: Simplify right side
   1,387.55x = 1,528,610.41
5. Step 5: Solve for x
   x = 1,528,610.41/1,387.55
6. Step 6: Final answer
   x = 1,101.66