Finding the Fourth Proportional to 10,890.69, 16,325.28 and 5,257.98

Step by Step Solution

1. Step 1: Write the proportion equation
   10,890.69 : 16,325.28 = 5,257.98 : x
2. Step 2: Convert to fraction form
   10,890.69/16,325.28 = 5,257.98/x
3. Step 3: Cross multiply
   10,890.69x = 16,325.28 × 5,257.98
4. Step 4: Simplify right side
   10,890.69x = 85,837,995.73
5. Step 5: Solve for x
   x = 85,837,995.73/10,890.69
6. Step 6: Final answer
   x = 7,881.78