Finding the Fourth Proportional to 28,486.78, 42,688.59 and 20,162.28

Step by Step Solution

1. Step 1: Write the proportion equation
   28,486.78 : 42,688.59 = 20,162.28 : x
2. Step 2: Convert to fraction form
   28,486.78/42,688.59 = 20,162.28/x
3. Step 3: Cross multiply
   28,486.78x = 42,688.59 × 20,162.28
4. Step 4: Simplify right side
   28,486.78x = 860,699,304.39
5. Step 5: Solve for x
   x = 860,699,304.39/28,486.78
6. Step 6: Final answer
   x = 30,213.99