Finding the Fourth Proportional to 10,667.21, 14,688.47 and 8,421.89

Step by Step Solution

1. Step 1: Write the proportion equation
   10,667.21 : 14,688.47 = 8,421.89 : x
2. Step 2: Convert to fraction form
   10,667.21/14,688.47 = 8,421.89/x
3. Step 3: Cross multiply
   10,667.21x = 14,688.47 × 8,421.89
4. Step 4: Simplify right side
   10,667.21x = 123,704,626.22
5. Step 5: Solve for x
   x = 123,704,626.22/10,667.21
6. Step 6: Final answer
   x = 11,596.72