Finding the Fourth Proportional to 9,907.72, 13,672.56 and 5,431.39

Step by Step Solution

1. Step 1: Write the proportion equation
   9,907.72 : 13,672.56 = 5,431.39 : x
2. Step 2: Convert to fraction form
   9,907.72/13,672.56 = 5,431.39/x
3. Step 3: Cross multiply
   9,907.72x = 13,672.56 × 5,431.39
4. Step 4: Simplify right side
   9,907.72x = 74,260,991.84
5. Step 5: Solve for x
   x = 74,260,991.84/9,907.72
6. Step 6: Final answer
   x = 7,495.27