Finding the Fourth Proportional to 72.24, 99.69 and 51.57

Step by Step Solution

1. Step 1: Write the proportion equation
   72.24 : 99.69 = 51.57 : x
2. Step 2: Convert to fraction form
   72.24/99.69 = 51.57/x
3. Step 3: Cross multiply
   72.24x = 99.69 × 51.57
4. Step 4: Simplify right side
   72.24x = 5,141.01
5. Step 5: Solve for x
   x = 5,141.01/72.24
6. Step 6: Final answer
   x = 71.17