Finding the Fourth Proportional to 5,128.43, 7,077.32 and 3,005.21

Step by Step Solution

1. Step 1: Write the proportion equation
   5,128.43 : 7,077.32 = 3,005.21 : x
2. Step 2: Convert to fraction form
   5,128.43/7,077.32 = 3,005.21/x
3. Step 3: Cross multiply
   5,128.43x = 7,077.32 × 3,005.21
4. Step 4: Simplify right side
   5,128.43x = 21,268,782.42
5. Step 5: Solve for x
   x = 21,268,782.42/5,128.43
6. Step 6: Final answer
   x = 4,147.23