Finding the Fourth Proportional to 1,388.88, 2,080.88 and 1,238.22

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.88 : 2,080.88 = 1,238.22 : x
2. Step 2: Convert to fraction form
   1,388.88/2,080.88 = 1,238.22/x
3. Step 3: Cross multiply
   1,388.88x = 2,080.88 × 1,238.22
4. Step 4: Simplify right side
   1,388.88x = 2,576,587.23
5. Step 5: Solve for x
   x = 2,576,587.23/1,388.88
6. Step 6: Final answer
   x = 1,855.15