Finding the Third Proportional to 42.12 and 91.90

Step by Step Solution

1. Step 1: Write the proportion equation
   42.12 : 91.90 = 91.90 : x
2. Step 2: Convert to fraction form
   42.12/91.90 = 91.90/x
3. Step 3: Cross multiply
   42.12x = 91.90 × 91.90
4. Step 4: Simplify right side
   42.12x = 8,445.32
5. Step 5: Solve for x
   x = 8,445.32/42.12
6. Step 6: Final answer
   x = 200.52