Home / 780-1,684

Finding the Third Proportional to 780 and 1,684

Calculator

Solution

The third proportional to 780 and 1,684 is: 3,635.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    780 : 1,684 = 1,684 : x
  2. Step 2: Convert to fraction form
    780/1,684 = 1,684/x
  3. Step 3: Cross multiply
    780x = 1,684 × 1,684
  4. Step 4: Simplify right side
    780x = 2,835,856
  5. Step 5: Solve for x
    x = 2,835,856/780
  6. Step 6: Final answer
    x = 3,635.71

Related Problems

Find third proportional to 390 and 842
Half scale
Find third proportional to 1,560 and 3,368
Double scale
Find third proportional to 782 and 1,688
Similar ratio
Find third proportional to 1,170 and 2,526
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (2.16) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.