Finding the Fourth Proportional to 42.72, 58.45 and 42.10

Step by Step Solution

1. Step 1: Write the proportion equation
   42.72 : 58.45 = 42.10 : x
2. Step 2: Convert to fraction form
   42.72/58.45 = 42.10/x
3. Step 3: Cross multiply
   42.72x = 58.45 × 42.10
4. Step 4: Simplify right side
   42.72x = 2,460.75
5. Step 5: Solve for x
   x = 2,460.75/42.72
6. Step 6: Final answer
   x = 57.60