Finding the Fourth Proportional to 103.31, 142.38 and 91.01

Step by Step Solution

1. Step 1: Write the proportion equation
   103.31 : 142.38 = 91.01 : x
2. Step 2: Convert to fraction form
   103.31/142.38 = 91.01/x
3. Step 3: Cross multiply
   103.31x = 142.38 × 91.01
4. Step 4: Simplify right side
   103.31x = 12,957.29
5. Step 5: Solve for x
   x = 12,957.29/103.31
6. Step 6: Final answer
   x = 125.43