Finding the Fourth Proportional to 72.74, 109.10 and 42.30

Step by Step Solution

1. Step 1: Write the proportion equation
   72.74 : 109.10 = 42.30 : x
2. Step 2: Convert to fraction form
   72.74/109.10 = 42.30/x
3. Step 3: Cross multiply
   72.74x = 109.10 × 42.30
4. Step 4: Simplify right side
   72.74x = 4,614.72
5. Step 5: Solve for x
   x = 4,614.72/72.74
6. Step 6: Final answer
   x = 63.45