Finding the Fourth Proportional to 1,123.88, 1,685.78 and 1,090.04

Step by Step Solution

1. Step 1: Write the proportion equation
   1,123.88 : 1,685.78 = 1,090.04 : x
2. Step 2: Convert to fraction form
   1,123.88/1,685.78 = 1,090.04/x
3. Step 3: Cross multiply
   1,123.88x = 1,685.78 × 1,090.04
4. Step 4: Simplify right side
   1,123.88x = 1,837,553.75
5. Step 5: Solve for x
   x = 1,837,553.75/1,123.88
6. Step 6: Final answer
   x = 1,635.02