Finding the Fourth Proportional to 10,905.50, 16,366.52 and 7,991.42

Step by Step Solution

1. Step 1: Write the proportion equation
   10,905.50 : 16,366.52 = 7,991.42 : x
2. Step 2: Convert to fraction form
   10,905.50/16,366.52 = 7,991.42/x
3. Step 3: Cross multiply
   10,905.50x = 16,366.52 × 7,991.42
4. Step 4: Simplify right side
   10,905.50x = 130,791,613.47
5. Step 5: Solve for x
   x = 130,791,613.47/10,905.50
6. Step 6: Final answer
   x = 11,993.18