Finding the Fourth Proportional to 2,116.35, 2,920.57 and 1,172.17

Step by Step Solution

1. Step 1: Write the proportion equation
   2,116.35 : 2,920.57 = 1,172.17 : x
2. Step 2: Convert to fraction form
   2,116.35/2,920.57 = 1,172.17/x
3. Step 3: Cross multiply
   2,116.35x = 2,920.57 × 1,172.17
4. Step 4: Simplify right side
   2,116.35x = 3,423,407.47
5. Step 5: Solve for x
   x = 3,423,407.47/2,116.35
6. Step 6: Final answer
   x = 1,617.60