Finding the Fourth Proportional to 67.80, 101.72 and 42.10

Step by Step Solution

1. Step 1: Write the proportion equation
   67.80 : 101.72 = 42.10 : x
2. Step 2: Convert to fraction form
   67.80/101.72 = 42.10/x
3. Step 3: Cross multiply
   67.80x = 101.72 × 42.10
4. Step 4: Simplify right side
   67.80x = 4,282.41
5. Step 5: Solve for x
   x = 4,282.41/67.80
6. Step 6: Final answer
   x = 63.16