Finding the Fourth Proportional to 71.29, 98.34 and 42.18

Step by Step Solution

1. Step 1: Write the proportion equation
   71.29 : 98.34 = 42.18 : x
2. Step 2: Convert to fraction form
   71.29/98.34 = 42.18/x
3. Step 3: Cross multiply
   71.29x = 98.34 × 42.18
4. Step 4: Simplify right side
   71.29x = 4,147.98
5. Step 5: Solve for x
   x = 4,147.98/71.29
6. Step 6: Final answer
   x = 58.18