Finding the Fourth Proportional to 78.94, 118.44 and 42.86

Step by Step Solution

1. Step 1: Write the proportion equation
   78.94 : 118.44 = 42.86 : x
2. Step 2: Convert to fraction form
   78.94/118.44 = 42.86/x
3. Step 3: Cross multiply
   78.94x = 118.44 × 42.86
4. Step 4: Simplify right side
   78.94x = 5,076.34
5. Step 5: Solve for x
   x = 5,076.34/78.94
6. Step 6: Final answer
   x = 64.31