Finding the Fourth Proportional to 9,415.21, 12,989.10 and 5,433.50

Step by Step Solution

1. Step 1: Write the proportion equation
   9,415.21 : 12,989.10 = 5,433.50 : x
2. Step 2: Convert to fraction form
   9,415.21/12,989.10 = 5,433.50/x
3. Step 3: Cross multiply
   9,415.21x = 12,989.10 × 5,433.50
4. Step 4: Simplify right side
   9,415.21x = 70,576,274.85
5. Step 5: Solve for x
   x = 70,576,274.85/9,415.21
6. Step 6: Final answer
   x = 7,495.99