Finding the Fourth Proportional to 1,247.56, 1,721.32 and 774.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,247.56 : 1,721.32 = 774.72 : x
2. Step 2: Convert to fraction form
   1,247.56/1,721.32 = 774.72/x
3. Step 3: Cross multiply
   1,247.56x = 1,721.32 × 774.72
4. Step 4: Simplify right side
   1,247.56x = 1,333,539.09
5. Step 5: Solve for x
   x = 1,333,539.09/1,247.56
6. Step 6: Final answer
   x = 1,068.92