Finding the Fourth Proportional to 2,565.16, 3,847.86 and 921.16

Step by Step Solution

1. Step 1: Write the proportion equation
   2,565.16 : 3,847.86 = 921.16 : x
2. Step 2: Convert to fraction form
   2,565.16/3,847.86 = 921.16/x
3. Step 3: Cross multiply
   2,565.16x = 3,847.86 × 921.16
4. Step 4: Simplify right side
   2,565.16x = 3,544,494.72
5. Step 5: Solve for x
   x = 3,544,494.72/2,565.16
6. Step 6: Final answer
   x = 1,381.78