Finding the Fourth Proportional to 78.43, 108.73 and 75.91

Step by Step Solution

1. Step 1: Write the proportion equation
   78.43 : 108.73 = 75.91 : x
2. Step 2: Convert to fraction form
   78.43/108.73 = 75.91/x
3. Step 3: Cross multiply
   78.43x = 108.73 × 75.91
4. Step 4: Simplify right side
   78.43x = 8,253.69
5. Step 5: Solve for x
   x = 8,253.69/78.43
6. Step 6: Final answer
   x = 105.24