Finding the Fourth Proportional to 1,568.61, 2,164.59 and 905.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,568.61 : 2,164.59 = 905.55 : x
2. Step 2: Convert to fraction form
   1,568.61/2,164.59 = 905.55/x
3. Step 3: Cross multiply
   1,568.61x = 2,164.59 × 905.55
4. Step 4: Simplify right side
   1,568.61x = 1,960,144.47
5. Step 5: Solve for x
   x = 1,960,144.47/1,568.61
6. Step 6: Final answer
   x = 1,249.61