Finding the Fourth Proportional to 9,309.78, 13,971.62 and 5,805.05

Step by Step Solution

1. Step 1: Write the proportion equation
   9,309.78 : 13,971.62 = 5,805.05 : x
2. Step 2: Convert to fraction form
   9,309.78/13,971.62 = 5,805.05/x
3. Step 3: Cross multiply
   9,309.78x = 13,971.62 × 5,805.05
4. Step 4: Simplify right side
   9,309.78x = 81,105,897.34
5. Step 5: Solve for x
   x = 81,105,897.34/9,309.78
6. Step 6: Final answer
   x = 8,711.90