Finding the Fourth Proportional to 1,100.86, 1,648.99 and 660.71

Step by Step Solution

1. Step 1: Write the proportion equation
   1,100.86 : 1,648.99 = 660.71 : x
2. Step 2: Convert to fraction form
   1,100.86/1,648.99 = 660.71/x
3. Step 3: Cross multiply
   1,100.86x = 1,648.99 × 660.71
4. Step 4: Simplify right side
   1,100.86x = 1,089,509.13
5. Step 5: Solve for x
   x = 1,089,509.13/1,100.86
6. Step 6: Final answer
   x = 989.69