Finding the Fourth Proportional to 42,789.41, 64,215.66 and 20,300.18

Step by Step Solution

1. Step 1: Write the proportion equation
   42,789.41 : 64,215.66 = 20,300.18 : x
2. Step 2: Convert to fraction form
   42,789.41/64,215.66 = 20,300.18/x
3. Step 3: Cross multiply
   42,789.41x = 64,215.66 × 20,300.18
4. Step 4: Simplify right side
   42,789.41x = 1,303,589,193.21
5. Step 5: Solve for x
   x = 1,303,589,193.21/42,789.41
6. Step 6: Final answer
   x = 30,465.23