Finding the Fourth Proportional to 58.50, 80.71 and 42.15

Step by Step Solution

1. Step 1: Write the proportion equation
   58.50 : 80.71 = 42.15 : x
2. Step 2: Convert to fraction form
   58.50/80.71 = 42.15/x
3. Step 3: Cross multiply
   58.50x = 80.71 × 42.15
4. Step 4: Simplify right side
   58.50x = 3,401.93
5. Step 5: Solve for x
   x = 3,401.93/58.50
6. Step 6: Final answer
   x = 58.15