Finding the Fourth Proportional to 3,856.72, 5,783.69 and 1,390.88

Step by Step Solution

1. Step 1: Write the proportion equation
   3,856.72 : 5,783.69 = 1,390.88 : x
2. Step 2: Convert to fraction form
   3,856.72/5,783.69 = 1,390.88/x
3. Step 3: Cross multiply
   3,856.72x = 5,783.69 × 1,390.88
4. Step 4: Simplify right side
   3,856.72x = 8,044,397.33
5. Step 5: Solve for x
   x = 8,044,397.33/3,856.72
6. Step 6: Final answer
   x = 2,085.81