Finding the Fourth Proportional to 30,967.93, 42,753.42 and 20,388.31

Step by Step Solution

1. Step 1: Write the proportion equation
   30,967.93 : 42,753.42 = 20,388.31 : x
2. Step 2: Convert to fraction form
   30,967.93/42,753.42 = 20,388.31/x
3. Step 3: Cross multiply
   30,967.93x = 42,753.42 × 20,388.31
4. Step 4: Simplify right side
   30,967.93x = 871,669,980.52
5. Step 5: Solve for x
   x = 871,669,980.52/30,967.93
6. Step 6: Final answer
   x = 28,147.51