Finding the Fourth Proportional to 72.68, 99.61 and 71.42

Step by Step Solution

1. Step 1: Write the proportion equation
   72.68 : 99.61 = 71.42 : x
2. Step 2: Convert to fraction form
   72.68/99.61 = 71.42/x
3. Step 3: Cross multiply
   72.68x = 99.61 × 71.42
4. Step 4: Simplify right side
   72.68x = 7,114.15
5. Step 5: Solve for x
   x = 7,114.15/72.68
6. Step 6: Final answer
   x = 97.88