Finding the Fourth Proportional to 2,565.56, 3,848.74 and 921.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,565.56 : 3,848.74 = 921.78 : x
2. Step 2: Convert to fraction form
   2,565.56/3,848.74 = 921.78/x
3. Step 3: Cross multiply
   2,565.56x = 3,848.74 × 921.78
4. Step 4: Simplify right side
   2,565.56x = 3,547,691.56
5. Step 5: Solve for x
   x = 3,547,691.56/2,565.56
6. Step 6: Final answer
   x = 1,382.81