Finding the Fourth Proportional to 9,921.48, 13,691.60 and 5,445.31

Step by Step Solution

1. Step 1: Write the proportion equation
   9,921.48 : 13,691.60 = 5,445.31 : x
2. Step 2: Convert to fraction form
   9,921.48/13,691.60 = 5,445.31/x
3. Step 3: Cross multiply
   9,921.48x = 13,691.60 × 5,445.31
4. Step 4: Simplify right side
   9,921.48x = 74,555,006.40
5. Step 5: Solve for x
   x = 74,555,006.40/9,921.48
6. Step 6: Final answer
   x = 7,514.50