Finding the Fourth Proportional to 2,109.86, 2,911.74 and 1,165.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,109.86 : 2,911.74 = 1,165.72 : x
2. Step 2: Convert to fraction form
   2,109.86/2,911.74 = 1,165.72/x
3. Step 3: Cross multiply
   2,109.86x = 2,911.74 × 1,165.72
4. Step 4: Simplify right side
   2,109.86x = 3,394,273.55
5. Step 5: Solve for x
   x = 3,394,273.55/2,109.86
6. Step 6: Final answer
   x = 1,608.77