Finding the Fourth Proportional to 9,907.76, 13,672.72 and 5,431.68

Step by Step Solution

1. Step 1: Write the proportion equation
   9,907.76 : 13,672.72 = 5,431.68 : x
2. Step 2: Convert to fraction form
   9,907.76/13,672.72 = 5,431.68/x
3. Step 3: Cross multiply
   9,907.76x = 13,672.72 × 5,431.68
4. Step 4: Simplify right side
   9,907.76x = 74,265,839.77
5. Step 5: Solve for x
   x = 74,265,839.77/9,907.76
6. Step 6: Final answer
   x = 7,495.72