Finding the Third Proportional to 42.36 and 85.57

Step by Step Solution

1. Step 1: Write the proportion equation
   42.36 : 85.57 = 85.57 : x
2. Step 2: Convert to fraction form
   42.36/85.57 = 85.57/x
3. Step 3: Cross multiply
   42.36x = 85.57 × 85.57
4. Step 4: Simplify right side
   42.36x = 7,322.28
5. Step 5: Solve for x
   x = 7,322.28/42.36
6. Step 6: Final answer
   x = 172.84