Finding the Fourth Proportional to 20,899.50, 28,854.82 and 12,950.16

Step by Step Solution

1. Step 1: Write the proportion equation
   20,899.50 : 28,854.82 = 12,950.16 : x
2. Step 2: Convert to fraction form
   20,899.50/28,854.82 = 12,950.16/x
3. Step 3: Cross multiply
   20,899.50x = 28,854.82 × 12,950.16
4. Step 4: Simplify right side
   20,899.50x = 373,674,370.91
5. Step 5: Solve for x
   x = 373,674,370.91/20,899.50
6. Step 6: Final answer
   x = 17,879.59