Finding the Third Proportional to 156.50 and 218.50

Step by Step Solution

1. Step 1: Write the proportion equation
   156.50 : 218.50 = 218.50 : x
2. Step 2: Convert to fraction form
   156.50/218.50 = 218.50/x
3. Step 3: Cross multiply
   156.50x = 218.50 × 218.50
4. Step 4: Simplify right side
   156.50x = 47,742.25
5. Step 5: Solve for x
   x = 47,742.25/156.50
6. Step 6: Final answer
   x = 305.06