Finding the Fourth Proportional to 11,117.86, 16,665.85 and 5,278.57

Step by Step Solution

1. Step 1: Write the proportion equation
   11,117.86 : 16,665.85 = 5,278.57 : x
2. Step 2: Convert to fraction form
   11,117.86/16,665.85 = 5,278.57/x
3. Step 3: Cross multiply
   11,117.86x = 16,665.85 × 5,278.57
4. Step 4: Simplify right side
   11,117.86x = 87,971,855.83
5. Step 5: Solve for x
   x = 87,971,855.83/11,117.86
6. Step 6: Final answer
   x = 7,912.66