Home / 155-218

Finding the Third Proportional to 155 and 218

Calculator

Solution

The third proportional to 155 and 218 is: 306.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    155 : 218 = 218 : x
  2. Step 2: Convert to fraction form
    155/218 = 218/x
  3. Step 3: Cross multiply
    155x = 218 × 218
  4. Step 4: Simplify right side
    155x = 47,524
  5. Step 5: Solve for x
    x = 47,524/155
  6. Step 6: Final answer
    x = 306.61

Related Problems

Find third proportional to 77.50 and 109
Half scale
Find third proportional to 310 and 436
Double scale
Find third proportional to 157 and 221
Similar ratio
Find third proportional to 232.50 and 327
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.41) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.