Finding the Fourth Proportional to 1,911.72, 2,638.95 and 1,165.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,911.72 : 2,638.95 = 1,165.89 : x
2. Step 2: Convert to fraction form
   1,911.72/2,638.95 = 1,165.89/x
3. Step 3: Cross multiply
   1,911.72x = 2,638.95 × 1,165.89
4. Step 4: Simplify right side
   1,911.72x = 3,076,725.42
5. Step 5: Solve for x
   x = 3,076,725.42/1,911.72
6. Step 6: Final answer
   x = 1,609.40