Finding the Fourth Proportional to 102.15, 152.91 and 71.76

Step by Step Solution

1. Step 1: Write the proportion equation
   102.15 : 152.91 = 71.76 : x
2. Step 2: Convert to fraction form
   102.15/152.91 = 71.76/x
3. Step 3: Cross multiply
   102.15x = 152.91 × 71.76
4. Step 4: Simplify right side
   102.15x = 10,972.82
5. Step 5: Solve for x
   x = 10,972.82/102.15
6. Step 6: Final answer
   x = 107.42