Finding the Fourth Proportional to 76.91, 115.31 and 42.69

Step by Step Solution

1. Step 1: Write the proportion equation
   76.91 : 115.31 = 42.69 : x
2. Step 2: Convert to fraction form
   76.91/115.31 = 42.69/x
3. Step 3: Cross multiply
   76.91x = 115.31 × 42.69
4. Step 4: Simplify right side
   76.91x = 4,922.37
5. Step 5: Solve for x
   x = 4,922.37/76.91
6. Step 6: Final answer
   x = 64.01