Finding the Fourth Proportional to 43.89, 66.18 and 42.50

Step by Step Solution

1. Step 1: Write the proportion equation
   43.89 : 66.18 = 42.50 : x
2. Step 2: Convert to fraction form
   43.89/66.18 = 42.50/x
3. Step 3: Cross multiply
   43.89x = 66.18 × 42.50
4. Step 4: Simplify right side
   43.89x = 2,812.32
5. Step 5: Solve for x
   x = 2,812.32/43.89
6. Step 6: Final answer
   x = 64.08