Finding the Fourth Proportional to 72.58, 100.12 and 56.18

Step by Step Solution

1. Step 1: Write the proportion equation
   72.58 : 100.12 = 56.18 : x
2. Step 2: Convert to fraction form
   72.58/100.12 = 56.18/x
3. Step 3: Cross multiply
   72.58x = 100.12 × 56.18
4. Step 4: Simplify right side
   72.58x = 5,624.74
5. Step 5: Solve for x
   x = 5,624.74/72.58
6. Step 6: Final answer
   x = 77.50