Finding the Fourth Proportional to 10,993.76, 15,166.12 and 7,215.40

Step by Step Solution

1. Step 1: Write the proportion equation
   10,993.76 : 15,166.12 = 7,215.40 : x
2. Step 2: Convert to fraction form
   10,993.76/15,166.12 = 7,215.40/x
3. Step 3: Cross multiply
   10,993.76x = 15,166.12 × 7,215.40
4. Step 4: Simplify right side
   10,993.76x = 109,429,622.25
5. Step 5: Solve for x
   x = 109,429,622.25/10,993.76
6. Step 6: Final answer
   x = 9,953.79