Home / 386.25-687

Finding the Third Proportional to 386.25 and 687

Calculator

Solution

The third proportional to 386.25 and 687 is: 1,221.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.25 : 687 = 687 : x
  2. Step 2: Convert to fraction form
    386.25/687 = 687/x
  3. Step 3: Cross multiply
    386.25x = 687 × 687
  4. Step 4: Simplify right side
    386.25x = 471,969
  5. Step 5: Solve for x
    x = 471,969/386.25
  6. Step 6: Final answer
    x = 1,221.93

Related Problems

Find third proportional to 193.13 and 343.50
Half scale
Find third proportional to 772.50 and 1,374
Double scale
Find third proportional to 388 and 691
Similar ratio
Find third proportional to 579.38 and 1,030.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.78) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.