Finding the Fourth Proportional to 28,642.82, 42,989.94 and 13,857.08

Step by Step Solution

1. Step 1: Write the proportion equation
   28,642.82 : 42,989.94 = 13,857.08 : x
2. Step 2: Convert to fraction form
   28,642.82/42,989.94 = 13,857.08/x
3. Step 3: Cross multiply
   28,642.82x = 42,989.94 × 13,857.08
4. Step 4: Simplify right side
   28,642.82x = 595,714,822.83
5. Step 5: Solve for x
   x = 595,714,822.83/28,642.82
6. Step 6: Final answer
   x = 20,798.05