Finding the Fourth Proportional to 69.91, 105.03 and 42.88

Step by Step Solution

1. Step 1: Write the proportion equation
   69.91 : 105.03 = 42.88 : x
2. Step 2: Convert to fraction form
   69.91/105.03 = 42.88/x
3. Step 3: Cross multiply
   69.91x = 105.03 × 42.88
4. Step 4: Simplify right side
   69.91x = 4,503.69
5. Step 5: Solve for x
   x = 4,503.69/69.91
6. Step 6: Final answer
   x = 64.42