Finding the Fourth Proportional to 2,659.61, 3,989.30 and 904.55

Step by Step Solution

1. Step 1: Write the proportion equation
   2,659.61 : 3,989.30 = 904.55 : x
2. Step 2: Convert to fraction form
   2,659.61/3,989.30 = 904.55/x
3. Step 3: Cross multiply
   2,659.61x = 3,989.30 × 904.55
4. Step 4: Simplify right side
   2,659.61x = 3,608,501.37
5. Step 5: Solve for x
   x = 3,608,501.37/2,659.61
6. Step 6: Final answer
   x = 1,356.78