Finding the Fourth Proportional to 3,889.16, 5,366.98 and 2,120.72

Step by Step Solution

1. Step 1: Write the proportion equation
   3,889.16 : 5,366.98 = 2,120.72 : x
2. Step 2: Convert to fraction form
   3,889.16/5,366.98 = 2,120.72/x
3. Step 3: Cross multiply
   3,889.16x = 5,366.98 × 2,120.72
4. Step 4: Simplify right side
   3,889.16x = 11,381,861.83
5. Step 5: Solve for x
   x = 11,381,861.83/3,889.16
6. Step 6: Final answer
   x = 2,926.56