Finding the Fourth Proportional to 3,786.15, 5,680.13 and 1,287.50

Step by Step Solution

1. Step 1: Write the proportion equation
   3,786.15 : 5,680.13 = 1,287.50 : x
2. Step 2: Convert to fraction form
   3,786.15/5,680.13 = 1,287.50/x
3. Step 3: Cross multiply
   3,786.15x = 5,680.13 × 1,287.50
4. Step 4: Simplify right side
   3,786.15x = 7,313,132.54
5. Step 5: Solve for x
   x = 7,313,132.54/3,786.15
6. Step 6: Final answer
   x = 1,931.55