Finding the Fourth Proportional to 1,101.86, 1,650.49 and 661.71

Step by Step Solution

1. Step 1: Write the proportion equation
   1,101.86 : 1,650.49 = 661.71 : x
2. Step 2: Convert to fraction form
   1,101.86/1,650.49 = 661.71/x
3. Step 3: Cross multiply
   1,101.86x = 1,650.49 × 661.71
4. Step 4: Simplify right side
   1,101.86x = 1,092,145.74
5. Step 5: Solve for x
   x = 1,092,145.74/1,101.86
6. Step 6: Final answer
   x = 991.18