Finding the Fourth Proportional to 28,405.69, 42,626.76 and 12,823.31

Step by Step Solution

1. Step 1: Write the proportion equation
   28,405.69 : 42,626.76 = 12,823.31 : x
2. Step 2: Convert to fraction form
   28,405.69/42,626.76 = 12,823.31/x
3. Step 3: Cross multiply
   28,405.69x = 42,626.76 × 12,823.31
4. Step 4: Simplify right side
   28,405.69x = 546,616,216.26
5. Step 5: Solve for x
   x = 546,616,216.26/28,405.69
6. Step 6: Final answer
   x = 19,243.20