Finding the Fourth Proportional to 20,910.24, 28,861.68 and 12,947.94

Step by Step Solution

1. Step 1: Write the proportion equation
   20,910.24 : 28,861.68 = 12,947.94 : x
2. Step 2: Convert to fraction form
   20,910.24/28,861.68 = 12,947.94/x
3. Step 3: Cross multiply
   20,910.24x = 28,861.68 × 12,947.94
4. Step 4: Simplify right side
   20,910.24x = 373,699,300.94
5. Step 5: Solve for x
   x = 373,699,300.94/20,910.24
6. Step 6: Final answer
   x = 17,871.59