Home / 690-831

Finding the Third Proportional to 690 and 831

Calculator

Solution

The third proportional to 690 and 831 is: 1,000.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    690 : 831 = 831 : x
  2. Step 2: Convert to fraction form
    690/831 = 831/x
  3. Step 3: Cross multiply
    690x = 831 × 831
  4. Step 4: Simplify right side
    690x = 690,561
  5. Step 5: Solve for x
    x = 690,561/690
  6. Step 6: Final answer
    x = 1,000.81

Related Problems

Find third proportional to 345 and 415.50
Half scale
Find third proportional to 1,380 and 1,662
Double scale
Find third proportional to 692 and 833
Similar ratio
Find third proportional to 1,035 and 1,246.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.20) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.