Finding the Fourth Proportional to 1,390.73, 2,090.88 and 1,118.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,390.73 : 2,090.88 = 1,118.72 : x
2. Step 2: Convert to fraction form
   1,390.73/2,090.88 = 1,118.72/x
3. Step 3: Cross multiply
   1,390.73x = 2,090.88 × 1,118.72
4. Step 4: Simplify right side
   1,390.73x = 2,339,114.50
5. Step 5: Solve for x
   x = 2,339,114.50/1,390.73
6. Step 6: Final answer
   x = 1,681.94