Finding the Fourth Proportional to 28,615.89, 42,934 and 12,819.68

Step by Step Solution

1. Step 1: Write the proportion equation
   28,615.89 : 42,934 = 12,819.68 : x
2. Step 2: Convert to fraction form
   28,615.89/42,934 = 12,819.68/x
3. Step 3: Cross multiply
   28,615.89x = 42,934 × 12,819.68
4. Step 4: Simplify right side
   28,615.89x = 550,400,141.12
5. Step 5: Solve for x
   x = 550,400,141.12/28,615.89
6. Step 6: Final answer
   x = 19,234.07