Finding the Fourth Proportional to 76.58, 105.76 and 54.86

Step by Step Solution

1. Step 1: Write the proportion equation
   76.58 : 105.76 = 54.86 : x
2. Step 2: Convert to fraction form
   76.58/105.76 = 54.86/x
3. Step 3: Cross multiply
   76.58x = 105.76 × 54.86
4. Step 4: Simplify right side
   76.58x = 5,801.72
5. Step 5: Solve for x
   x = 5,801.72/76.58
6. Step 6: Final answer
   x = 75.76