Finding the Fourth Proportional to 42.91, 59.16 and 31.23

Step by Step Solution

1. Step 1: Write the proportion equation
   42.91 : 59.16 = 31.23 : x
2. Step 2: Convert to fraction form
   42.91/59.16 = 31.23/x
3. Step 3: Cross multiply
   42.91x = 59.16 × 31.23
4. Step 4: Simplify right side
   42.91x = 1,847.68
5. Step 5: Solve for x
   x = 1,847.68/42.91
6. Step 6: Final answer
   x = 43.06