Finding the Fourth Proportional to 13,398.72, 18,486.72 and 7,805.76

Step by Step Solution

1. Step 1: Write the proportion equation
   13,398.72 : 18,486.72 = 7,805.76 : x
2. Step 2: Convert to fraction form
   13,398.72/18,486.72 = 7,805.76/x
3. Step 3: Cross multiply
   13,398.72x = 18,486.72 × 7,805.76
4. Step 4: Simplify right side
   13,398.72x = 144,302,899.51
5. Step 5: Solve for x
   x = 144,302,899.51/13,398.72
6. Step 6: Final answer
   x = 10,769.90