Home / 7.69-12.75

Finding the Third Proportional to 7.69 and 12.75

Calculator

Solution

The third proportional to 7.69 and 12.75 is: 21.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    7.69 : 12.75 = 12.75 : x
  2. Step 2: Convert to fraction form
    7.69/12.75 = 12.75/x
  3. Step 3: Cross multiply
    7.69x = 12.75 × 12.75
  4. Step 4: Simplify right side
    7.69x = 162.56
  5. Step 5: Solve for x
    x = 162.56/7.69
  6. Step 6: Final answer
    x = 21.15

Related Problems

Find third proportional to 3.84 and 6.38
Half scale
Find third proportional to 15.38 and 25.50
Double scale
Find third proportional to 10 and 16
Similar ratio
Find third proportional to 11.53 and 19.13
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.66) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.