Finding the Fourth Proportional to 42,715.47, 64,086.91 and 20,530.45

Step by Step Solution

1. Step 1: Write the proportion equation
   42,715.47 : 64,086.91 = 20,530.45 : x
2. Step 2: Convert to fraction form
   42,715.47/64,086.91 = 20,530.45/x
3. Step 3: Cross multiply
   42,715.47x = 64,086.91 × 20,530.45
4. Step 4: Simplify right side
   42,715.47x = 1,315,732,889.87
5. Step 5: Solve for x
   x = 1,315,732,889.87/42,715.47
6. Step 6: Final answer
   x = 30,802.26