Finding the Fourth Proportional to 78.72, 118.05 and 30.59

Step by Step Solution

1. Step 1: Write the proportion equation
   78.72 : 118.05 = 30.59 : x
2. Step 2: Convert to fraction form
   78.72/118.05 = 30.59/x
3. Step 3: Cross multiply
   78.72x = 118.05 × 30.59
4. Step 4: Simplify right side
   78.72x = 3,611.15
5. Step 5: Solve for x
   x = 3,611.15/78.72
6. Step 6: Final answer
   x = 45.87