Finding the Fourth Proportional to 72.99, 109.42 and 42.50

Step by Step Solution

1. Step 1: Write the proportion equation
   72.99 : 109.42 = 42.50 : x
2. Step 2: Convert to fraction form
   72.99/109.42 = 42.50/x
3. Step 3: Cross multiply
   72.99x = 109.42 × 42.50
4. Step 4: Simplify right side
   72.99x = 4,650.35
5. Step 5: Solve for x
   x = 4,650.35/72.99
6. Step 6: Final answer
   x = 63.71