Finding the Fourth Proportional to 21,916.84, 30,243.72 and 12,357.07

Step by Step Solution

1. Step 1: Write the proportion equation
   21,916.84 : 30,243.72 = 12,357.07 : x
2. Step 2: Convert to fraction form
   21,916.84/30,243.72 = 12,357.07/x
3. Step 3: Cross multiply
   21,916.84x = 30,243.72 × 12,357.07
4. Step 4: Simplify right side
   21,916.84x = 373,723,769.67
5. Step 5: Solve for x
   x = 373,723,769.67/21,916.84
6. Step 6: Final answer
   x = 17,051.90