Finding the Fourth Proportional to 10,990.48, 15,191.78 and 10,118.58

Step by Step Solution

1. Step 1: Write the proportion equation
   10,990.48 : 15,191.78 = 10,118.58 : x
2. Step 2: Convert to fraction form
   10,990.48/15,191.78 = 10,118.58/x
3. Step 3: Cross multiply
   10,990.48x = 15,191.78 × 10,118.58
4. Step 4: Simplify right side
   10,990.48x = 153,719,241.27
5. Step 5: Solve for x
   x = 153,719,241.27/10,990.48
6. Step 6: Final answer
   x = 13,986.58