Finding the Fourth Proportional to 1,185.90, 1,787.73 and 1,106.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,185.90 : 1,787.73 = 1,106.61 : x
2. Step 2: Convert to fraction form
   1,185.90/1,787.73 = 1,106.61/x
3. Step 3: Cross multiply
   1,185.90x = 1,787.73 × 1,106.61
4. Step 4: Simplify right side
   1,185.90x = 1,978,319.90
5. Step 5: Solve for x
   x = 1,978,319.90/1,185.90
6. Step 6: Final answer
   x = 1,668.20