Finding the Fourth Proportional to 9,907.86, 13,672.83 and 5,431.77

Step by Step Solution

1. Step 1: Write the proportion equation
   9,907.86 : 13,672.83 = 5,431.77 : x
2. Step 2: Convert to fraction form
   9,907.86/13,672.83 = 5,431.77/x
3. Step 3: Cross multiply
   9,907.86x = 13,672.83 × 5,431.77
4. Step 4: Simplify right side
   9,907.86x = 74,267,667.81
5. Step 5: Solve for x
   x = 74,267,667.81/9,907.86
6. Step 6: Final answer
   x = 7,495.83