Finding the Fourth Proportional to 1,118.71, 1,539.30 and 1,090.09

Step by Step Solution

1. Step 1: Write the proportion equation
   1,118.71 : 1,539.30 = 1,090.09 : x
2. Step 2: Convert to fraction form
   1,118.71/1,539.30 = 1,090.09/x
3. Step 3: Cross multiply
   1,118.71x = 1,539.30 × 1,090.09
4. Step 4: Simplify right side
   1,118.71x = 1,677,975.54
5. Step 5: Solve for x
   x = 1,677,975.54/1,118.71
6. Step 6: Final answer
   x = 1,499.92