Finding the Fourth Proportional to 2,651.64, 3,978.90 and 1,113.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,651.64 : 3,978.90 = 1,113.72 : x
2. Step 2: Convert to fraction form
   2,651.64/3,978.90 = 1,113.72/x
3. Step 3: Cross multiply
   2,651.64x = 3,978.90 × 1,113.72
4. Step 4: Simplify right side
   2,651.64x = 4,431,380.51
5. Step 5: Solve for x
   x = 4,431,380.51/2,651.64
6. Step 6: Final answer
   x = 1,671.18