Finding the Fourth Proportional to 1,399.56, 1,931.46 and 840.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,399.56 : 1,931.46 = 840.06 : x
2. Step 2: Convert to fraction form
   1,399.56/1,931.46 = 840.06/x
3. Step 3: Cross multiply
   1,399.56x = 1,931.46 × 840.06
4. Step 4: Simplify right side
   1,399.56x = 1,622,542.29
5. Step 5: Solve for x
   x = 1,622,542.29/1,399.56
6. Step 6: Final answer
   x = 1,159.32