Home / 320.25-678.75

Finding the Third Proportional to 320.25 and 678.75

Calculator

Solution

The third proportional to 320.25 and 678.75 is: 1,438.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    320.25 : 678.75 = 678.75 : x
  2. Step 2: Convert to fraction form
    320.25/678.75 = 678.75/x
  3. Step 3: Cross multiply
    320.25x = 678.75 × 678.75
  4. Step 4: Simplify right side
    320.25x = 460,701.56
  5. Step 5: Solve for x
    x = 460,701.56/320.25
  6. Step 6: Final answer
    x = 1,438.57

Related Problems

Find third proportional to 160.13 and 339.38
Half scale
Find third proportional to 640.50 and 1,357.50
Double scale
Find third proportional to 322 and 683
Similar ratio
Find third proportional to 480.38 and 1,018.13
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (2.12) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.