Finding the Fourth Proportional to 69.12, 103.78 and 42.10

Step by Step Solution

1. Step 1: Write the proportion equation
   69.12 : 103.78 = 42.10 : x
2. Step 2: Convert to fraction form
   69.12/103.78 = 42.10/x
3. Step 3: Cross multiply
   69.12x = 103.78 × 42.10
4. Step 4: Simplify right side
   69.12x = 4,369.14
5. Step 5: Solve for x
   x = 4,369.14/69.12
6. Step 6: Final answer
   x = 63.21