Finding the Fourth Proportional to 2,859.48, 4,288.86 and 1,215.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,859.48 : 4,288.86 = 1,215.72 : x
2. Step 2: Convert to fraction form
   2,859.48/4,288.86 = 1,215.72/x
3. Step 3: Cross multiply
   2,859.48x = 4,288.86 × 1,215.72
4. Step 4: Simplify right side
   2,859.48x = 5,214,052.88
5. Step 5: Solve for x
   x = 5,214,052.88/2,859.48
6. Step 6: Final answer
   x = 1,823.43