Finding the Fourth Proportional to 79.61, 118.53 and 78.47

Step by Step Solution

1. Step 1: Write the proportion equation
   79.61 : 118.53 = 78.47 : x
2. Step 2: Convert to fraction form
   79.61/118.53 = 78.47/x
3. Step 3: Cross multiply
   79.61x = 118.53 × 78.47
4. Step 4: Simplify right side
   79.61x = 9,300.83
5. Step 5: Solve for x
   x = 9,300.83/79.61
6. Step 6: Final answer
   x = 116.83