Finding the Fourth Proportional to 28,662.39, 42,930.86 and 20,317.10

Step by Step Solution

1. Step 1: Write the proportion equation
   28,662.39 : 42,930.86 = 20,317.10 : x
2. Step 2: Convert to fraction form
   28,662.39/42,930.86 = 20,317.10/x
3. Step 3: Cross multiply
   28,662.39x = 42,930.86 × 20,317.10
4. Step 4: Simplify right side
   28,662.39x = 872,230,259.47
5. Step 5: Solve for x
   x = 872,230,259.47/28,662.39
6. Step 6: Final answer
   x = 30,431.18