Finding the Fourth Proportional to 62.88, 86.72 and 42.12

Step by Step Solution

1. Step 1: Write the proportion equation
   62.88 : 86.72 = 42.12 : x
2. Step 2: Convert to fraction form
   62.88/86.72 = 42.12/x
3. Step 3: Cross multiply
   62.88x = 86.72 × 42.12
4. Step 4: Simplify right side
   62.88x = 3,652.65
5. Step 5: Solve for x
   x = 3,652.65/62.88
6. Step 6: Final answer
   x = 58.09