Finding the Fourth Proportional to 42,128.64, 63,231.84 and 21,366.72

Step by Step Solution

1. Step 1: Write the proportion equation
   42,128.64 : 63,231.84 = 21,366.72 : x
2. Step 2: Convert to fraction form
   42,128.64/63,231.84 = 21,366.72/x
3. Step 3: Cross multiply
   42,128.64x = 63,231.84 × 21,366.72
4. Step 4: Simplify right side
   42,128.64x = 1,351,057,020.36
5. Step 5: Solve for x
   x = 1,351,057,020.36/42,128.64
6. Step 6: Final answer
   x = 32,069.80