Finding the Fourth Proportional to 117.72, 162.50 and 76.31

Step by Step Solution

1. Step 1: Write the proportion equation
   117.72 : 162.50 = 76.31 : x
2. Step 2: Convert to fraction form
   117.72/162.50 = 76.31/x
3. Step 3: Cross multiply
   117.72x = 162.50 × 76.31
4. Step 4: Simplify right side
   117.72x = 12,399.37
5. Step 5: Solve for x
   x = 12,399.37/117.72
6. Step 6: Final answer
   x = 105.33