Finding the Fourth Proportional to 3,784.57, 5,222.70 and 2,128.57

Step by Step Solution

1. Step 1: Write the proportion equation
   3,784.57 : 5,222.70 = 2,128.57 : x
2. Step 2: Convert to fraction form
   3,784.57/5,222.70 = 2,128.57/x
3. Step 3: Cross multiply
   3,784.57x = 5,222.70 × 2,128.57
4. Step 4: Simplify right side
   3,784.57x = 11,116,882.54
5. Step 5: Solve for x
   x = 11,116,882.54/3,784.57
6. Step 6: Final answer
   x = 2,937.42