Finding the Fourth Proportional to 2,079.86, 3,121.16 and 909.81

Step by Step Solution

1. Step 1: Write the proportion equation
   2,079.86 : 3,121.16 = 909.81 : x
2. Step 2: Convert to fraction form
   2,079.86/3,121.16 = 909.81/x
3. Step 3: Cross multiply
   2,079.86x = 3,121.16 × 909.81
4. Step 4: Simplify right side
   2,079.86x = 2,839,658.03
5. Step 5: Solve for x
   x = 2,839,658.03/2,079.86
6. Step 6: Final answer
   x = 1,365.32