Home / 111-138

Finding the Third Proportional to 111 and 138

Calculator

Solution

The third proportional to 111 and 138 is: 171.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    111 : 138 = 138 : x
  2. Step 2: Convert to fraction form
    111/138 = 138/x
  3. Step 3: Cross multiply
    111x = 138 × 138
  4. Step 4: Simplify right side
    111x = 19,044
  5. Step 5: Solve for x
    x = 19,044/111
  6. Step 6: Final answer
    x = 171.57

Related Problems

Find third proportional to 55.50 and 69
Half scale
Find third proportional to 222 and 276
Double scale
Find third proportional to 113 and 140
Similar ratio
Find third proportional to 166.50 and 207
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.24) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.