Finding the Fourth Proportional to 92.88, 138.56 and 78.53

Step by Step Solution

1. Step 1: Write the proportion equation
   92.88 : 138.56 = 78.53 : x
2. Step 2: Convert to fraction form
   92.88/138.56 = 78.53/x
3. Step 3: Cross multiply
   92.88x = 138.56 × 78.53
4. Step 4: Simplify right side
   92.88x = 10,880.33
5. Step 5: Solve for x
   x = 10,880.33/92.88
6. Step 6: Final answer
   x = 117.14