Finding the Fourth Proportional to 2,158.86, 2,978.31 and 1,361.91

Step by Step Solution

1. Step 1: Write the proportion equation
   2,158.86 : 2,978.31 = 1,361.91 : x
2. Step 2: Convert to fraction form
   2,158.86/2,978.31 = 1,361.91/x
3. Step 3: Cross multiply
   2,158.86x = 2,978.31 × 1,361.91
4. Step 4: Simplify right side
   2,158.86x = 4,056,190.17
5. Step 5: Solve for x
   x = 4,056,190.17/2,158.86
6. Step 6: Final answer
   x = 1,878.86