Finding the Fourth Proportional to 2,158.47, 2,978.62 and 1,214.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,158.47 : 2,978.62 = 1,214.31 : x
2. Step 2: Convert to fraction form
   2,158.47/2,978.62 = 1,214.31/x
3. Step 3: Cross multiply
   2,158.47x = 2,978.62 × 1,214.31
4. Step 4: Simplify right side
   2,158.47x = 3,616,968.05
5. Step 5: Solve for x
   x = 3,616,968.05/2,158.47
6. Step 6: Final answer
   x = 1,675.71