Finding the Fourth Proportional to 72.56, 100.09 and 50.78

Step by Step Solution

1. Step 1: Write the proportion equation
   72.56 : 100.09 = 50.78 : x
2. Step 2: Convert to fraction form
   72.56/100.09 = 50.78/x
3. Step 3: Cross multiply
   72.56x = 100.09 × 50.78
4. Step 4: Simplify right side
   72.56x = 5,082.57
5. Step 5: Solve for x
   x = 5,082.57/72.56
6. Step 6: Final answer
   x = 70.05