Finding the Fourth Proportional to 31,007.81, 42,791.69 and 16,861.57

Step by Step Solution

1. Step 1: Write the proportion equation
   31,007.81 : 42,791.69 = 16,861.57 : x
2. Step 2: Convert to fraction form
   31,007.81/42,791.69 = 16,861.57/x
3. Step 3: Cross multiply
   31,007.81x = 42,791.69 × 16,861.57
4. Step 4: Simplify right side
   31,007.81x = 721,535,011.53
5. Step 5: Solve for x
   x = 721,535,011.53/31,007.81
6. Step 6: Final answer
   x = 23,269.46