Finding the Fourth Proportional to 3,870.13, 5,340.78 and 2,101.76

Step by Step Solution

1. Step 1: Write the proportion equation
   3,870.13 : 5,340.78 = 2,101.76 : x
2. Step 2: Convert to fraction form
   3,870.13/5,340.78 = 2,101.76/x
3. Step 3: Cross multiply
   3,870.13x = 5,340.78 × 2,101.76
4. Step 4: Simplify right side
   3,870.13x = 11,225,045.87
5. Step 5: Solve for x
   x = 11,225,045.87/3,870.13
6. Step 6: Final answer
   x = 2,900.43