Finding the Fourth Proportional to 3,870, 5,340.71 and 2,101.61

Step by Step Solution

1. Step 1: Write the proportion equation
   3,870 : 5,340.71 = 2,101.61 : x
2. Step 2: Convert to fraction form
   3,870/5,340.71 = 2,101.61/x
3. Step 3: Cross multiply
   3,870x = 5,340.71 × 2,101.61
4. Step 4: Simplify right side
   3,870x = 11,224,052.33
5. Step 5: Solve for x
   x = 11,224,052.33/3,870
6. Step 6: Final answer
   x = 2,900.27