Finding the Fourth Proportional to 2,116.91, 2,921.23 and 1,172.63

Step by Step Solution

1. Step 1: Write the proportion equation
   2,116.91 : 2,921.23 = 1,172.63 : x
2. Step 2: Convert to fraction form
   2,116.91/2,921.23 = 1,172.63/x
3. Step 3: Cross multiply
   2,116.91x = 2,921.23 × 1,172.63
4. Step 4: Simplify right side
   2,116.91x = 3,425,526.31
5. Step 5: Solve for x
   x = 3,425,526.31/2,116.91
6. Step 6: Final answer
   x = 1,618.18