Home / 691-791

Finding the Third Proportional to 691 and 791

Calculator

Solution

The third proportional to 691 and 791 is: 905.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    691 : 791 = 791 : x
  2. Step 2: Convert to fraction form
    691/791 = 791/x
  3. Step 3: Cross multiply
    691x = 791 × 791
  4. Step 4: Simplify right side
    691x = 625,681
  5. Step 5: Solve for x
    x = 625,681/691
  6. Step 6: Final answer
    x = 905.47

Related Problems

Find third proportional to 345.50 and 395.50
Half scale
Find third proportional to 1,382 and 1,582
Double scale
Find third proportional to 693 and 793
Similar ratio
Find third proportional to 1,036.50 and 1,186.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.14) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.