Finding the Fourth Proportional to 1,236.78, 1,709.10 and 1,026.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,236.78 : 1,709.10 = 1,026.72 : x
2. Step 2: Convert to fraction form
   1,236.78/1,709.10 = 1,026.72/x
3. Step 3: Cross multiply
   1,236.78x = 1,709.10 × 1,026.72
4. Step 4: Simplify right side
   1,236.78x = 1,754,767.15
5. Step 5: Solve for x
   x = 1,754,767.15/1,236.78
6. Step 6: Final answer
   x = 1,418.82