Finding the Fourth Proportional to 42,857.51, 64,249.25 and 20,686.46

Step by Step Solution

1. Step 1: Write the proportion equation
   42,857.51 : 64,249.25 = 20,686.46 : x
2. Step 2: Convert to fraction form
   42,857.51/64,249.25 = 20,686.46/x
3. Step 3: Cross multiply
   42,857.51x = 64,249.25 × 20,686.46
4. Step 4: Simplify right side
   42,857.51x = 1,329,089,115.48
5. Step 5: Solve for x
   x = 1,329,089,115.48/42,857.51
6. Step 6: Final answer
   x = 31,011.82