Finding the Third Proportional to 78.98 and 121.86

Step by Step Solution

1. Step 1: Write the proportion equation
   78.98 : 121.86 = 121.86 : x
2. Step 2: Convert to fraction form
   78.98/121.86 = 121.86/x
3. Step 3: Cross multiply
   78.98x = 121.86 × 121.86
4. Step 4: Simplify right side
   78.98x = 14,849.71
5. Step 5: Solve for x
   x = 14,849.71/78.98
6. Step 6: Final answer
   x = 188.01