Finding the Fourth Proportional to 1,619.55, 2,234.60 and 921.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,619.55 : 2,234.60 = 921.31 : x
2. Step 2: Convert to fraction form
   1,619.55/2,234.60 = 921.31/x
3. Step 3: Cross multiply
   1,619.55x = 2,234.60 × 921.31
4. Step 4: Simplify right side
   1,619.55x = 2,058,754.72
5. Step 5: Solve for x
   x = 2,058,754.72/1,619.55
6. Step 6: Final answer
   x = 1,271.19