Finding the Fourth Proportional to 2,116.37, 2,920.73 and 1,172.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,116.37 : 2,920.73 = 1,172.20 : x
2. Step 2: Convert to fraction form
   2,116.37/2,920.73 = 1,172.20/x
3. Step 3: Cross multiply
   2,116.37x = 2,920.73 × 1,172.20
4. Step 4: Simplify right side
   2,116.37x = 3,423,679.71
5. Step 5: Solve for x
   x = 3,423,679.71/2,116.37
6. Step 6: Final answer
   x = 1,617.71