Finding the Fourth Proportional to 83.05, 124.53 and 42.55

Step by Step Solution

1. Step 1: Write the proportion equation
   83.05 : 124.53 = 42.55 : x
2. Step 2: Convert to fraction form
   83.05/124.53 = 42.55/x
3. Step 3: Cross multiply
   83.05x = 124.53 × 42.55
4. Step 4: Simplify right side
   83.05x = 5,298.54
5. Step 5: Solve for x
   x = 5,298.54/83.05
6. Step 6: Final answer
   x = 63.80