Finding the Fourth Proportional to 11.86, 17.69 and 10.61

Step by Step Solution

1. Step 1: Write the proportion equation
   11.86 : 17.69 = 10.61 : x
2. Step 2: Convert to fraction form
   11.86/17.69 = 10.61/x
3. Step 3: Cross multiply
   11.86x = 17.69 × 10.61
4. Step 4: Simplify right side
   11.86x = 187.63
5. Step 5: Solve for x
   x = 187.63/11.86
6. Step 6: Final answer
   x = 15.82