Finding the Fourth Proportional to 9,405.99, 12,979.71 and 5,156.22

Step by Step Solution

1. Step 1: Write the proportion equation
   9,405.99 : 12,979.71 = 5,156.22 : x
2. Step 2: Convert to fraction form
   9,405.99/12,979.71 = 5,156.22/x
3. Step 3: Cross multiply
   9,405.99x = 12,979.71 × 5,156.22
4. Step 4: Simplify right side
   9,405.99x = 66,926,240.30
5. Step 5: Solve for x
   x = 66,926,240.30/9,405.99
6. Step 6: Final answer
   x = 7,115.28