Finding the Fourth Proportional to 3,700.57, 5,106.87 and 2,128.75

Step by Step Solution

1. Step 1: Write the proportion equation
   3,700.57 : 5,106.87 = 2,128.75 : x
2. Step 2: Convert to fraction form
   3,700.57/5,106.87 = 2,128.75/x
3. Step 3: Cross multiply
   3,700.57x = 5,106.87 × 2,128.75
4. Step 4: Simplify right side
   3,700.57x = 10,871,249.51
5. Step 5: Solve for x
   x = 10,871,249.51/3,700.57
6. Step 6: Final answer
   x = 2,937.72