Finding the Fourth Proportional to 42,715.17, 64,085.75 and 20,243.06

Step by Step Solution

1. Step 1: Write the proportion equation
   42,715.17 : 64,085.75 = 20,243.06 : x
2. Step 2: Convert to fraction form
   42,715.17/64,085.75 = 20,243.06/x
3. Step 3: Cross multiply
   42,715.17x = 64,085.75 × 20,243.06
4. Step 4: Simplify right side
   42,715.17x = 1,297,291,682.40
5. Step 5: Solve for x
   x = 1,297,291,682.40/42,715.17
6. Step 6: Final answer
   x = 30,370.75