Finding the Fourth Proportional to 2,101.44, 3,147.84 and 1,638.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,101.44 : 3,147.84 = 1,638.72 : x
2. Step 2: Convert to fraction form
   2,101.44/3,147.84 = 1,638.72/x
3. Step 3: Cross multiply
   2,101.44x = 3,147.84 × 1,638.72
4. Step 4: Simplify right side
   2,101.44x = 5,158,428.36
5. Step 5: Solve for x
   x = 5,158,428.36/2,101.44
6. Step 6: Final answer
   x = 2,454.71