Finding the Fourth Proportional to 9,409.35, 12,986.60 and 5,429.91

Step by Step Solution

1. Step 1: Write the proportion equation
   9,409.35 : 12,986.60 = 5,429.91 : x
2. Step 2: Convert to fraction form
   9,409.35/12,986.60 = 5,429.91/x
3. Step 3: Cross multiply
   9,409.35x = 12,986.60 × 5,429.91
4. Step 4: Simplify right side
   9,409.35x = 70,516,069.21
5. Step 5: Solve for x
   x = 70,516,069.21/9,409.35
6. Step 6: Final answer
   x = 7,494.26