Finding the Fourth Proportional to 69.93, 104.78 and 53.91

Step by Step Solution

1. Step 1: Write the proportion equation
   69.93 : 104.78 = 53.91 : x
2. Step 2: Convert to fraction form
   69.93/104.78 = 53.91/x
3. Step 3: Cross multiply
   69.93x = 104.78 × 53.91
4. Step 4: Simplify right side
   69.93x = 5,648.42
5. Step 5: Solve for x
   x = 5,648.42/69.93
6. Step 6: Final answer
   x = 80.77