Finding the Fourth Proportional to 42.78, 59.31 and 42.06

Step by Step Solution

1. Step 1: Write the proportion equation
   42.78 : 59.31 = 42.06 : x
2. Step 2: Convert to fraction form
   42.78/59.31 = 42.06/x
3. Step 3: Cross multiply
   42.78x = 59.31 × 42.06
4. Step 4: Simplify right side
   42.78x = 2,494.58
5. Step 5: Solve for x
   x = 2,494.58/42.78
6. Step 6: Final answer
   x = 58.31