Finding the Fourth Proportional to 7,128.69, 9,838.16 and 4,145.10

Step by Step Solution

1. Step 1: Write the proportion equation
   7,128.69 : 9,838.16 = 4,145.10 : x
2. Step 2: Convert to fraction form
   7,128.69/9,838.16 = 4,145.10/x
3. Step 3: Cross multiply
   7,128.69x = 9,838.16 × 4,145.10
4. Step 4: Simplify right side
   7,128.69x = 40,780,157.02
5. Step 5: Solve for x
   x = 40,780,157.02/7,128.69
6. Step 6: Final answer
   x = 5,720.57