Finding the Fourth Proportional to 72.09, 99.63 and 57.51

Step by Step Solution

1. Step 1: Write the proportion equation
   72.09 : 99.63 = 57.51 : x
2. Step 2: Convert to fraction form
   72.09/99.63 = 57.51/x
3. Step 3: Cross multiply
   72.09x = 99.63 × 57.51
4. Step 4: Simplify right side
   72.09x = 5,729.72
5. Step 5: Solve for x
   x = 5,729.72/72.09
6. Step 6: Final answer
   x = 79.48