Finding the Fourth Proportional to 30,571.36, 42,206.88 and 19,978.72

Step by Step Solution

1. Step 1: Write the proportion equation
   30,571.36 : 42,206.88 = 19,978.72 : x
2. Step 2: Convert to fraction form
   30,571.36/42,206.88 = 19,978.72/x
3. Step 3: Cross multiply
   30,571.36x = 42,206.88 × 19,978.72
4. Step 4: Simplify right side
   30,571.36x = 843,239,437.59
5. Step 5: Solve for x
   x = 843,239,437.59/30,571.36
6. Step 6: Final answer
   x = 27,582.66