Finding the Fourth Proportional to 42.87, 58.69 and 42.57

Step by Step Solution

1. Step 1: Write the proportion equation
   42.87 : 58.69 = 42.57 : x
2. Step 2: Convert to fraction form
   42.87/58.69 = 42.57/x
3. Step 3: Cross multiply
   42.87x = 58.69 × 42.57
4. Step 4: Simplify right side
   42.87x = 2,498.33
5. Step 5: Solve for x
   x = 2,498.33/42.87
6. Step 6: Final answer
   x = 58.28