Finding the Fourth Proportional to 1,434.78, 1,980.42 and 1,240.38

Step by Step Solution

1. Step 1: Write the proportion equation
   1,434.78 : 1,980.42 = 1,240.38 : x
2. Step 2: Convert to fraction form
   1,434.78/1,980.42 = 1,240.38/x
3. Step 3: Cross multiply
   1,434.78x = 1,980.42 × 1,240.38
4. Step 4: Simplify right side
   1,434.78x = 2,456,473.36
5. Step 5: Solve for x
   x = 2,456,473.36/1,434.78
6. Step 6: Final answer
   x = 1,712.09