Finding the Fourth Proportional to 11,987.27, 17,990.32 and 8,315.34

Step by Step Solution

1. Step 1: Write the proportion equation
   11,987.27 : 17,990.32 = 8,315.34 : x
2. Step 2: Convert to fraction form
   11,987.27/17,990.32 = 8,315.34/x
3. Step 3: Cross multiply
   11,987.27x = 17,990.32 × 8,315.34
4. Step 4: Simplify right side
   11,987.27x = 149,595,627.51
5. Step 5: Solve for x
   x = 149,595,627.51/11,987.27
6. Step 6: Final answer
   x = 12,479.54