Finding the Fourth Proportional to 72.90, 100.62 and 51.12

Step by Step Solution

1. Step 1: Write the proportion equation
   72.90 : 100.62 = 51.12 : x
2. Step 2: Convert to fraction form
   72.90/100.62 = 51.12/x
3. Step 3: Cross multiply
   72.90x = 100.62 × 51.12
4. Step 4: Simplify right side
   72.90x = 5,143.69
5. Step 5: Solve for x
   x = 5,143.69/72.90
6. Step 6: Final answer
   x = 70.56