Home / 77-121

Finding the Third Proportional to 77 and 121

Calculator

Solution

The third proportional to 77 and 121 is: 190.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    77 : 121 = 121 : x
  2. Step 2: Convert to fraction form
    77/121 = 121/x
  3. Step 3: Cross multiply
    77x = 121 × 121
  4. Step 4: Simplify right side
    77x = 14,641
  5. Step 5: Solve for x
    x = 14,641/77
  6. Step 6: Final answer
    x = 190.14

Related Problems

Find third proportional to 38.50 and 60.50
Half scale
Find third proportional to 154 and 242
Double scale
Find third proportional to 79 and 124
Similar ratio
Find third proportional to 115.50 and 181.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.57) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.