Finding the Fourth Proportional to 2,806.56, 3,870.72 and 2,106.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,806.56 : 3,870.72 = 2,106.72 : x
2. Step 2: Convert to fraction form
   2,806.56/3,870.72 = 2,106.72/x
3. Step 3: Cross multiply
   2,806.56x = 3,870.72 × 2,106.72
4. Step 4: Simplify right side
   2,806.56x = 8,154,523.24
5. Step 5: Solve for x
   x = 8,154,523.24/2,806.56
6. Step 6: Final answer
   x = 2,905.52