Finding the Fourth Proportional to 1,978.62, 2,967.85 and 939.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,978.62 : 2,967.85 = 939.12 : x
2. Step 2: Convert to fraction form
   1,978.62/2,967.85 = 939.12/x
3. Step 3: Cross multiply
   1,978.62x = 2,967.85 × 939.12
4. Step 4: Simplify right side
   1,978.62x = 2,787,167.29
5. Step 5: Solve for x
   x = 2,787,167.29/1,978.62
6. Step 6: Final answer
   x = 1,408.64