Finding the Fourth Proportional to 78.77, 118.06 and 42.63

Step by Step Solution

1. Step 1: Write the proportion equation
   78.77 : 118.06 = 42.63 : x
2. Step 2: Convert to fraction form
   78.77/118.06 = 42.63/x
3. Step 3: Cross multiply
   78.77x = 118.06 × 42.63
4. Step 4: Simplify right side
   78.77x = 5,032.35
5. Step 5: Solve for x
   x = 5,032.35/78.77
6. Step 6: Final answer
   x = 63.88