Finding the Fourth Proportional to 3,886.16, 5,362.84 and 2,117.72

Step by Step Solution

1. Step 1: Write the proportion equation
   3,886.16 : 5,362.84 = 2,117.72 : x
2. Step 2: Convert to fraction form
   3,886.16/5,362.84 = 2,117.72/x
3. Step 3: Cross multiply
   3,886.16x = 5,362.84 × 2,117.72
4. Step 4: Simplify right side
   3,886.16x = 11,356,993.52
5. Step 5: Solve for x
   x = 11,356,993.52/3,886.16
6. Step 6: Final answer
   x = 2,922.42