Finding the Fourth Proportional to 3,856.78, 5,784.53 and 1,259.72

Step by Step Solution

1. Step 1: Write the proportion equation
   3,856.78 : 5,784.53 = 1,259.72 : x
2. Step 2: Convert to fraction form
   3,856.78/5,784.53 = 1,259.72/x
3. Step 3: Cross multiply
   3,856.78x = 5,784.53 × 1,259.72
4. Step 4: Simplify right side
   3,856.78x = 7,286,852.91
5. Step 5: Solve for x
   x = 7,286,852.91/3,856.78
6. Step 6: Final answer
   x = 1,889.36