Finding the Fourth Proportional to 2,116.38, 2,920.55 and 1,172.14

Step by Step Solution

1. Step 1: Write the proportion equation
   2,116.38 : 2,920.55 = 1,172.14 : x
2. Step 2: Convert to fraction form
   2,116.38/2,920.55 = 1,172.14/x
3. Step 3: Cross multiply
   2,116.38x = 2,920.55 × 1,172.14
4. Step 4: Simplify right side
   2,116.38x = 3,423,280.31
5. Step 5: Solve for x
   x = 3,423,280.31/2,116.38
6. Step 6: Final answer
   x = 1,617.51