Finding the Fourth Proportional to 2,155.72, 3,232.56 and 840.08

Step by Step Solution

1. Step 1: Write the proportion equation
   2,155.72 : 3,232.56 = 840.08 : x
2. Step 2: Convert to fraction form
   2,155.72/3,232.56 = 840.08/x
3. Step 3: Cross multiply
   2,155.72x = 3,232.56 × 840.08
4. Step 4: Simplify right side
   2,155.72x = 2,715,609.00
5. Step 5: Solve for x
   x = 2,715,609.00/2,155.72
6. Step 6: Final answer
   x = 1,259.72