Finding the Fourth Proportional to 3,911.72, 5,867.11 and 990.05

Step by Step Solution

1. Step 1: Write the proportion equation
   3,911.72 : 5,867.11 = 990.05 : x
2. Step 2: Convert to fraction form
   3,911.72/5,867.11 = 990.05/x
3. Step 3: Cross multiply
   3,911.72x = 5,867.11 × 990.05
4. Step 4: Simplify right side
   3,911.72x = 5,808,727.31
5. Step 5: Solve for x
   x = 5,808,727.31/3,911.72
6. Step 6: Final answer
   x = 1,484.95