Finding the Fourth Proportional to 103.31, 142.64 and 72.22

Step by Step Solution

1. Step 1: Write the proportion equation
   103.31 : 142.64 = 72.22 : x
2. Step 2: Convert to fraction form
   103.31/142.64 = 72.22/x
3. Step 3: Cross multiply
   103.31x = 142.64 × 72.22
4. Step 4: Simplify right side
   103.31x = 10,300.74
5. Step 5: Solve for x
   x = 10,300.74/103.31
6. Step 6: Final answer
   x = 99.70