Finding the Fourth Proportional to 2,072.22, 3,109.41 and 840.54

Step by Step Solution

1. Step 1: Write the proportion equation
   2,072.22 : 3,109.41 = 840.54 : x
2. Step 2: Convert to fraction form
   2,072.22/3,109.41 = 840.54/x
3. Step 3: Cross multiply
   2,072.22x = 3,109.41 × 840.54
4. Step 4: Simplify right side
   2,072.22x = 2,613,583.48
5. Step 5: Solve for x
   x = 2,613,583.48/2,072.22
6. Step 6: Final answer
   x = 1,261.25