Finding the Fourth Proportional to 72.25, 99.70 and 42.75

Step by Step Solution

1. Step 1: Write the proportion equation
   72.25 : 99.70 = 42.75 : x
2. Step 2: Convert to fraction form
   72.25/99.70 = 42.75/x
3. Step 3: Cross multiply
   72.25x = 99.70 × 42.75
4. Step 4: Simplify right side
   72.25x = 4,262.18
5. Step 5: Solve for x
   x = 4,262.18/72.25
6. Step 6: Final answer
   x = 58.99