Finding the Fourth Proportional to 42,786.54, 64,152.47 and 20,555.69

Step by Step Solution

1. Step 1: Write the proportion equation
   42,786.54 : 64,152.47 = 20,555.69 : x
2. Step 2: Convert to fraction form
   42,786.54/64,152.47 = 20,555.69/x
3. Step 3: Cross multiply
   42,786.54x = 64,152.47 × 20,555.69
4. Step 4: Simplify right side
   42,786.54x = 1,318,698,016.68
5. Step 5: Solve for x
   x = 1,318,698,016.68/42,786.54
6. Step 6: Final answer
   x = 30,820.39