Finding the Fourth Proportional to 21,769.76, 30,045.05 and 12,818.10

Step by Step Solution

1. Step 1: Write the proportion equation
   21,769.76 : 30,045.05 = 12,818.10 : x
2. Step 2: Convert to fraction form
   21,769.76/30,045.05 = 12,818.10/x
3. Step 3: Cross multiply
   21,769.76x = 30,045.05 × 12,818.10
4. Step 4: Simplify right side
   21,769.76x = 385,120,419.10
5. Step 5: Solve for x
   x = 385,120,419.10/21,769.76
6. Step 6: Final answer
   x = 17,690.61