Finding the Fourth Proportional to 42.36, 58.09 and 42.15

Step by Step Solution

1. Step 1: Write the proportion equation
   42.36 : 58.09 = 42.15 : x
2. Step 2: Convert to fraction form
   42.36/58.09 = 42.15/x
3. Step 3: Cross multiply
   42.36x = 58.09 × 42.15
4. Step 4: Simplify right side
   42.36x = 2,448.49
5. Step 5: Solve for x
   x = 2,448.49/42.36
6. Step 6: Final answer
   x = 57.80