Home / 108-128

Finding the Third Proportional to 108 and 128

Calculator

Solution

The third proportional to 108 and 128 is: 151.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    108 : 128 = 128 : x
  2. Step 2: Convert to fraction form
    108/128 = 128/x
  3. Step 3: Cross multiply
    108x = 128 × 128
  4. Step 4: Simplify right side
    108x = 16,384
  5. Step 5: Solve for x
    x = 16,384/108
  6. Step 6: Final answer
    x = 151.70

Related Problems

Find third proportional to 54 and 64
Half scale
Find third proportional to 216 and 256
Double scale
Find third proportional to 110 and 130
Similar ratio
Find third proportional to 162 and 192
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.19) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.