Finding the Fourth Proportional to 69.30, 103.89 and 42.21

Step by Step Solution

1. Step 1: Write the proportion equation
   69.30 : 103.89 = 42.21 : x
2. Step 2: Convert to fraction form
   69.30/103.89 = 42.21/x
3. Step 3: Cross multiply
   69.30x = 103.89 × 42.21
4. Step 4: Simplify right side
   69.30x = 4,385.55
5. Step 5: Solve for x
   x = 4,385.55/69.30
6. Step 6: Final answer
   x = 63.29