Finding the Fourth Proportional to 1,274.96, 1,910.52 and 840.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,274.96 : 1,910.52 = 840.56 : x
2. Step 2: Convert to fraction form
   1,274.96/1,910.52 = 840.56/x
3. Step 3: Cross multiply
   1,274.96x = 1,910.52 × 840.56
4. Step 4: Simplify right side
   1,274.96x = 1,605,906.69
5. Step 5: Solve for x
   x = 1,605,906.69/1,274.96
6. Step 6: Final answer
   x = 1,259.57