Finding the Fourth Proportional to 5,128.56, 7,075.74 and 3,111.24

Step by Step Solution

1. Step 1: Write the proportion equation
   5,128.56 : 7,075.74 = 3,111.24 : x
2. Step 2: Convert to fraction form
   5,128.56/7,075.74 = 3,111.24/x
3. Step 3: Cross multiply
   5,128.56x = 7,075.74 × 3,111.24
4. Step 4: Simplify right side
   5,128.56x = 22,014,325.32
5. Step 5: Solve for x
   x = 22,014,325.32/5,128.56
6. Step 6: Final answer
   x = 4,292.50