Finding the Fourth Proportional to 10.39, 15.56 and 5.05

Step by Step Solution

1. Step 1: Write the proportion equation
   10.39 : 15.56 = 5.05 : x
2. Step 2: Convert to fraction form
   10.39/15.56 = 5.05/x
3. Step 3: Cross multiply
   10.39x = 15.56 × 5.05
4. Step 4: Simplify right side
   10.39x = 78.50
5. Step 5: Solve for x
   x = 78.50/10.39
6. Step 6: Final answer
   x = 7.56