Home / 640-881

Finding the Third Proportional to 640 and 881

Calculator

Solution

The third proportional to 640 and 881 is: 1,212.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    640 : 881 = 881 : x
  2. Step 2: Convert to fraction form
    640/881 = 881/x
  3. Step 3: Cross multiply
    640x = 881 × 881
  4. Step 4: Simplify right side
    640x = 776,161
  5. Step 5: Solve for x
    x = 776,161/640
  6. Step 6: Final answer
    x = 1,212.75

Related Problems

Find third proportional to 320 and 440.50
Half scale
Find third proportional to 1,280 and 1,762
Double scale
Find third proportional to 642 and 884
Similar ratio
Find third proportional to 960 and 1,321.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.