Finding the Fourth Proportional to 72.58, 100.15 and 39.83

Step by Step Solution

1. Step 1: Write the proportion equation
   72.58 : 100.15 = 39.83 : x
2. Step 2: Convert to fraction form
   72.58/100.15 = 39.83/x
3. Step 3: Cross multiply
   72.58x = 100.15 × 39.83
4. Step 4: Simplify right side
   72.58x = 3,988.37
5. Step 5: Solve for x
   x = 3,988.37/72.58
6. Step 6: Final answer
   x = 54.95