Home / 121.13-138.19

Finding the Third Proportional to 121.13 and 138.19

Calculator

Solution

The third proportional to 121.13 and 138.19 is: 157.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.13 : 138.19 = 138.19 : x
  2. Step 2: Convert to fraction form
    121.13/138.19 = 138.19/x
  3. Step 3: Cross multiply
    121.13x = 138.19 × 138.19
  4. Step 4: Simplify right side
    121.13x = 19,095.79
  5. Step 5: Solve for x
    x = 19,095.79/121.13
  6. Step 6: Final answer
    x = 157.65

Related Problems

Find third proportional to 60.56 and 69.09
Half scale
Find third proportional to 242.25 and 276.38
Double scale
Find third proportional to 123 and 140
Similar ratio
Find third proportional to 181.69 and 207.28
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.14) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.