Finding the Fourth Proportional to 72.56, 108.64 and 53.15

Step by Step Solution

1. Step 1: Write the proportion equation
   72.56 : 108.64 = 53.15 : x
2. Step 2: Convert to fraction form
   72.56/108.64 = 53.15/x
3. Step 3: Cross multiply
   72.56x = 108.64 × 53.15
4. Step 4: Simplify right side
   72.56x = 5,774.71
5. Step 5: Solve for x
   x = 5,774.71/72.56
6. Step 6: Final answer
   x = 79.59