Finding the Fourth Proportional to 42.69, 58.94 and 28.90

Step by Step Solution

1. Step 1: Write the proportion equation
   42.69 : 58.94 = 28.90 : x
2. Step 2: Convert to fraction form
   42.69/58.94 = 28.90/x
3. Step 3: Cross multiply
   42.69x = 58.94 × 28.90
4. Step 4: Simplify right side
   42.69x = 1,703.37
5. Step 5: Solve for x
   x = 1,703.37/42.69
6. Step 6: Final answer
   x = 39.90