Home / 61-128

Finding the Third Proportional to 61 and 128

Calculator

Solution

The third proportional to 61 and 128 is: 268.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    61 : 128 = 128 : x
  2. Step 2: Convert to fraction form
    61/128 = 128/x
  3. Step 3: Cross multiply
    61x = 128 × 128
  4. Step 4: Simplify right side
    61x = 16,384
  5. Step 5: Solve for x
    x = 16,384/61
  6. Step 6: Final answer
    x = 268.59

Related Problems

Find third proportional to 30.50 and 64
Half scale
Find third proportional to 122 and 256
Double scale
Find third proportional to 63 and 132
Similar ratio
Find third proportional to 91.50 and 192
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (2.10) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.