Finding the Fourth Proportional to 5,128.21, 7,075.55 and 3,002.57

Step by Step Solution

1. Step 1: Write the proportion equation
   5,128.21 : 7,075.55 = 3,002.57 : x
2. Step 2: Convert to fraction form
   5,128.21/7,075.55 = 3,002.57/x
3. Step 3: Cross multiply
   5,128.21x = 7,075.55 × 3,002.57
4. Step 4: Simplify right side
   5,128.21x = 21,244,832.83
5. Step 5: Solve for x
   x = 21,244,832.83/5,128.21
6. Step 6: Final answer
   x = 4,142.74