Finding the Fourth Proportional to 10,890.56, 16,336.18 and 5,190.30

Step by Step Solution

1. Step 1: Write the proportion equation
   10,890.56 : 16,336.18 = 5,190.30 : x
2. Step 2: Convert to fraction form
   10,890.56/16,336.18 = 5,190.30/x
3. Step 3: Cross multiply
   10,890.56x = 16,336.18 × 5,190.30
4. Step 4: Simplify right side
   10,890.56x = 84,789,675.05
5. Step 5: Solve for x
   x = 84,789,675.05/10,890.56
6. Step 6: Final answer
   x = 7,785.61