Finding the Fourth Proportional to 2,991.72, 4,128.42 and 1,665.42

Step by Step Solution

1. Step 1: Write the proportion equation
   2,991.72 : 4,128.42 = 1,665.42 : x
2. Step 2: Convert to fraction form
   2,991.72/4,128.42 = 1,665.42/x
3. Step 3: Cross multiply
   2,991.72x = 4,128.42 × 1,665.42
4. Step 4: Simplify right side
   2,991.72x = 6,875,553.24
5. Step 5: Solve for x
   x = 6,875,553.24/2,991.72
6. Step 6: Final answer
   x = 2,298.19