Finding the Fourth Proportional to 2,116.95, 2,921.34 and 1,172.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,116.95 : 2,921.34 = 1,172.72 : x
2. Step 2: Convert to fraction form
   2,116.95/2,921.34 = 1,172.72/x
3. Step 3: Cross multiply
   2,116.95x = 2,921.34 × 1,172.72
4. Step 4: Simplify right side
   2,116.95x = 3,425,913.84
5. Step 5: Solve for x
   x = 3,425,913.84/2,116.95
6. Step 6: Final answer
   x = 1,618.33