Finding the Fourth Proportional to 10,987.76, 15,157.86 and 7,209.38

Step by Step Solution

1. Step 1: Write the proportion equation
   10,987.76 : 15,157.86 = 7,209.38 : x
2. Step 2: Convert to fraction form
   10,987.76/15,157.86 = 7,209.38/x
3. Step 3: Cross multiply
   10,987.76x = 15,157.86 × 7,209.38
4. Step 4: Simplify right side
   10,987.76x = 109,278,772.73
5. Step 5: Solve for x
   x = 109,278,772.73/10,987.76
6. Step 6: Final answer
   x = 9,945.50