Finding the Fourth Proportional to 7,868.79, 10,861.88 and 5,217.09

Step by Step Solution

1. Step 1: Write the proportion equation
   7,868.79 : 10,861.88 = 5,217.09 : x
2. Step 2: Convert to fraction form
   7,868.79/10,861.88 = 5,217.09/x
3. Step 3: Cross multiply
   7,868.79x = 10,861.88 × 5,217.09
4. Step 4: Simplify right side
   7,868.79x = 56,667,379.44
5. Step 5: Solve for x
   x = 56,667,379.44/7,868.79
6. Step 6: Final answer
   x = 7,201.54