Finding the Fourth Proportional to 1,288.56, 1,778.28 and 846.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,288.56 : 1,778.28 = 846.72 : x
2. Step 2: Convert to fraction form
   1,288.56/1,778.28 = 846.72/x
3. Step 3: Cross multiply
   1,288.56x = 1,778.28 × 846.72
4. Step 4: Simplify right side
   1,288.56x = 1,505,705.24
5. Step 5: Solve for x
   x = 1,505,705.24/1,288.56
6. Step 6: Final answer
   x = 1,168.52