Finding the Fourth Proportional to 67.19, 100.69 and 42.79

Step by Step Solution

1. Step 1: Write the proportion equation
   67.19 : 100.69 = 42.79 : x
2. Step 2: Convert to fraction form
   67.19/100.69 = 42.79/x
3. Step 3: Cross multiply
   67.19x = 100.69 × 42.79
4. Step 4: Simplify right side
   67.19x = 4,308.53
5. Step 5: Solve for x
   x = 4,308.53/67.19
6. Step 6: Final answer
   x = 64.12