Finding the Fourth Proportional to 20,916.86, 31,379.98 and 7,065.50

Step by Step Solution

1. Step 1: Write the proportion equation
   20,916.86 : 31,379.98 = 7,065.50 : x
2. Step 2: Convert to fraction form
   20,916.86/31,379.98 = 7,065.50/x
3. Step 3: Cross multiply
   20,916.86x = 31,379.98 × 7,065.50
4. Step 4: Simplify right side
   20,916.86x = 221,715,248.69
5. Step 5: Solve for x
   x = 221,715,248.69/20,916.86
6. Step 6: Final answer
   x = 10,599.83