Finding the Fourth Proportional to 77.05, 115.50 and 42.83

Step by Step Solution

1. Step 1: Write the proportion equation
   77.05 : 115.50 = 42.83 : x
2. Step 2: Convert to fraction form
   77.05/115.50 = 42.83/x
3. Step 3: Cross multiply
   77.05x = 115.50 × 42.83
4. Step 4: Simplify right side
   77.05x = 4,946.07
5. Step 5: Solve for x
   x = 4,946.07/77.05
6. Step 6: Final answer
   x = 64.20