Finding the Fourth Proportional to 90.58, 124.89 and 78.88

Step by Step Solution

1. Step 1: Write the proportion equation
   90.58 : 124.89 = 78.88 : x
2. Step 2: Convert to fraction form
   90.58/124.89 = 78.88/x
3. Step 3: Cross multiply
   90.58x = 124.89 × 78.88
4. Step 4: Simplify right side
   90.58x = 9,851.32
5. Step 5: Solve for x
   x = 9,851.32/90.58
6. Step 6: Final answer
   x = 108.76