Home / 389-878

Finding the Third Proportional to 389 and 878

Calculator

Solution

The third proportional to 389 and 878 is: 1,981.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    389 : 878 = 878 : x
  2. Step 2: Convert to fraction form
    389/878 = 878/x
  3. Step 3: Cross multiply
    389x = 878 × 878
  4. Step 4: Simplify right side
    389x = 770,884
  5. Step 5: Solve for x
    x = 770,884/389
  6. Step 6: Final answer
    x = 1,981.71

Related Problems

Find third proportional to 194.50 and 439
Half scale
Find third proportional to 778 and 1,756
Double scale
Find third proportional to 391 and 883
Similar ratio
Find third proportional to 583.50 and 1,317
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (2.26) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.