Finding the Fourth Proportional to 10.56, 15.76 and 10.42

Step by Step Solution

1. Step 1: Write the proportion equation
   10.56 : 15.76 = 10.42 : x
2. Step 2: Convert to fraction form
   10.56/15.76 = 10.42/x
3. Step 3: Cross multiply
   10.56x = 15.76 × 10.42
4. Step 4: Simplify right side
   10.56x = 164.22
5. Step 5: Solve for x
   x = 164.22/10.56
6. Step 6: Final answer
   x = 15.55