Home / 89-138

Finding the Third Proportional to 89 and 138

Calculator

Solution

The third proportional to 89 and 138 is: 213.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    89 : 138 = 138 : x
  2. Step 2: Convert to fraction form
    89/138 = 138/x
  3. Step 3: Cross multiply
    89x = 138 × 138
  4. Step 4: Simplify right side
    89x = 19,044
  5. Step 5: Solve for x
    x = 19,044/89
  6. Step 6: Final answer
    x = 213.98

Related Problems

Find third proportional to 44.50 and 69
Half scale
Find third proportional to 178 and 276
Double scale
Find third proportional to 91 and 141
Similar ratio
Find third proportional to 133.50 and 207
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.55) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.