Finding the Fourth Proportional to 3,870.15, 5,340.80 and 2,101.75

Step by Step Solution

1. Step 1: Write the proportion equation
   3,870.15 : 5,340.80 = 2,101.75 : x
2. Step 2: Convert to fraction form
   3,870.15/5,340.80 = 2,101.75/x
3. Step 3: Cross multiply
   3,870.15x = 5,340.80 × 2,101.75
4. Step 4: Simplify right side
   3,870.15x = 11,225,018.30
5. Step 5: Solve for x
   x = 11,225,018.30/3,870.15
6. Step 6: Final answer
   x = 2,900.41