Finding the Fourth Proportional to 30,921.42, 42,655.23 and 21,972.54

Step by Step Solution

1. Step 1: Write the proportion equation
   30,921.42 : 42,655.23 = 21,972.54 : x
2. Step 2: Convert to fraction form
   30,921.42/42,655.23 = 21,972.54/x
3. Step 3: Cross multiply
   30,921.42x = 42,655.23 × 21,972.54
4. Step 4: Simplify right side
   30,921.42x = 937,243,747.38
5. Step 5: Solve for x
   x = 937,243,747.38/30,921.42
6. Step 6: Final answer
   x = 30,310.50