Finding the Fourth Proportional to 1,290.16, 1,780.41 and 1,103.41

Step by Step Solution

1. Step 1: Write the proportion equation
   1,290.16 : 1,780.41 = 1,103.41 : x
2. Step 2: Convert to fraction form
   1,290.16/1,780.41 = 1,103.41/x
3. Step 3: Cross multiply
   1,290.16x = 1,780.41 × 1,103.41
4. Step 4: Simplify right side
   1,290.16x = 1,964,522.20
5. Step 5: Solve for x
   x = 1,964,522.20/1,290.16
6. Step 6: Final answer
   x = 1,522.70