Finding the Fourth Proportional to 5,640.32, 7,784.56 and 3,870.48

Step by Step Solution

1. Step 1: Write the proportion equation
   5,640.32 : 7,784.56 = 3,870.48 : x
2. Step 2: Convert to fraction form
   5,640.32/7,784.56 = 3,870.48/x
3. Step 3: Cross multiply
   5,640.32x = 7,784.56 × 3,870.48
4. Step 4: Simplify right side
   5,640.32x = 30,129,983.79
5. Step 5: Solve for x
   x = 30,129,983.79/5,640.32
6. Step 6: Final answer
   x = 5,341.89