Finding the Fourth Proportional to 13,311.78, 19,971.50 and 4,305.69

Step by Step Solution

1. Step 1: Write the proportion equation
   13,311.78 : 19,971.50 = 4,305.69 : x
2. Step 2: Convert to fraction form
   13,311.78/19,971.50 = 4,305.69/x
3. Step 3: Cross multiply
   13,311.78x = 19,971.50 × 4,305.69
4. Step 4: Simplify right side
   13,311.78x = 85,991,066.31
5. Step 5: Solve for x
   x = 85,991,066.31/13,311.78
6. Step 6: Final answer
   x = 6,459.77