Finding the Fourth Proportional to 42,987.45, 64,460.41 and 18,020.79

Step by Step Solution

1. Step 1: Write the proportion equation
   42,987.45 : 64,460.41 = 18,020.79 : x
2. Step 2: Convert to fraction form
   42,987.45/64,460.41 = 18,020.79/x
3. Step 3: Cross multiply
   42,987.45x = 64,460.41 × 18,020.79
4. Step 4: Simplify right side
   42,987.45x = 1,161,627,511.92
5. Step 5: Solve for x
   x = 1,161,627,511.92/42,987.45
6. Step 6: Final answer
   x = 27,022.48