Finding the Fourth Proportional to 76.81, 106.00 and 42.31

Step by Step Solution

1. Step 1: Write the proportion equation
   76.81 : 106.00 = 42.31 : x
2. Step 2: Convert to fraction form
   76.81/106.00 = 42.31/x
3. Step 3: Cross multiply
   76.81x = 106.00 × 42.31
4. Step 4: Simplify right side
   76.81x = 4,485.18
5. Step 5: Solve for x
   x = 4,485.18/76.81
6. Step 6: Final answer
   x = 58.39