Finding the Fourth Proportional to 30,583.12, 42,189.16 and 19,978.96

Step by Step Solution

1. Step 1: Write the proportion equation
   30,583.12 : 42,189.16 = 19,978.96 : x
2. Step 2: Convert to fraction form
   30,583.12/42,189.16 = 19,978.96/x
3. Step 3: Cross multiply
   30,583.12x = 42,189.16 × 19,978.96
4. Step 4: Simplify right side
   30,583.12x = 842,895,540.07
5. Step 5: Solve for x
   x = 842,895,540.07/30,583.12
6. Step 6: Final answer
   x = 27,560.81