Home / 281-690

Finding the Third Proportional to 281 and 690

Calculator

Solution

The third proportional to 281 and 690 is: 1,694.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    281 : 690 = 690 : x
  2. Step 2: Convert to fraction form
    281/690 = 690/x
  3. Step 3: Cross multiply
    281x = 690 × 690
  4. Step 4: Simplify right side
    281x = 476,100
  5. Step 5: Solve for x
    x = 476,100/281
  6. Step 6: Final answer
    x = 1,694.31

Related Problems

Find third proportional to 140.50 and 345
Half scale
Find third proportional to 562 and 1,380
Double scale
Find third proportional to 283 and 695
Similar ratio
Find third proportional to 421.50 and 1,035
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (2.46) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.