Finding the Fourth Proportional to 42,972.72, 64,460.84 and 20,471.84

Step by Step Solution

1. Step 1: Write the proportion equation
   42,972.72 : 64,460.84 = 20,471.84 : x
2. Step 2: Convert to fraction form
   42,972.72/64,460.84 = 20,471.84/x
3. Step 3: Cross multiply
   42,972.72x = 64,460.84 × 20,471.84
4. Step 4: Simplify right side
   42,972.72x = 1,319,632,002.75
5. Step 5: Solve for x
   x = 1,319,632,002.75/42,972.72
6. Step 6: Final answer
   x = 30,708.60