Home / 689-1,290

Finding the Third Proportional to 689 and 1,290

Calculator

Solution

The third proportional to 689 and 1,290 is: 2,415.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    689 : 1,290 = 1,290 : x
  2. Step 2: Convert to fraction form
    689/1,290 = 1,290/x
  3. Step 3: Cross multiply
    689x = 1,290 × 1,290
  4. Step 4: Simplify right side
    689x = 1,664,100
  5. Step 5: Solve for x
    x = 1,664,100/689
  6. Step 6: Final answer
    x = 2,415.24

Related Problems

Why These Related Problems?

These problems maintain the same ratio (1.87) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.