Finding the Fourth Proportional to 71.46, 107.31 and 53.18

Step by Step Solution

1. Step 1: Write the proportion equation
   71.46 : 107.31 = 53.18 : x
2. Step 2: Convert to fraction form
   71.46/107.31 = 53.18/x
3. Step 3: Cross multiply
   71.46x = 107.31 × 53.18
4. Step 4: Simplify right side
   71.46x = 5,707.04
5. Step 5: Solve for x
   x = 5,707.04/71.46
6. Step 6: Final answer
   x = 79.87