Finding the Fourth Proportional to 21,870.79, 30,182.67 and 12,313.96

Step by Step Solution

1. Step 1: Write the proportion equation
   21,870.79 : 30,182.67 = 12,313.96 : x
2. Step 2: Convert to fraction form
   21,870.79/30,182.67 = 12,313.96/x
3. Step 3: Cross multiply
   21,870.79x = 30,182.67 × 12,313.96
4. Step 4: Simplify right side
   21,870.79x = 371,668,228.80
5. Step 5: Solve for x
   x = 371,668,228.80/21,870.79
6. Step 6: Final answer
   x = 16,993.82