Home / 120-255

Finding the Third Proportional to 120 and 255

Calculator

Solution

The third proportional to 120 and 255 is: 541.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    120 : 255 = 255 : x
  2. Step 2: Convert to fraction form
    120/255 = 255/x
  3. Step 3: Cross multiply
    120x = 255 × 255
  4. Step 4: Simplify right side
    120x = 65,025
  5. Step 5: Solve for x
    x = 65,025/120
  6. Step 6: Final answer
    x = 541.88

Related Problems

Find third proportional to 60 and 127.50
Half scale
Find third proportional to 240 and 510
Double scale
Find third proportional to 122 and 259
Similar ratio
Find third proportional to 180 and 382.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (2.13) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.