Finding the Fourth Proportional to 2,116.56, 2,920.89 and 1,172.40

Step by Step Solution

1. Step 1: Write the proportion equation
   2,116.56 : 2,920.89 = 1,172.40 : x
2. Step 2: Convert to fraction form
   2,116.56/2,920.89 = 1,172.40/x
3. Step 3: Cross multiply
   2,116.56x = 2,920.89 × 1,172.40
4. Step 4: Simplify right side
   2,116.56x = 3,424,451.44
5. Step 5: Solve for x
   x = 3,424,451.44/2,116.56
6. Step 6: Final answer
   x = 1,617.93