Home / 201-421

Finding the Third Proportional to 201 and 421

Calculator

Solution

The third proportional to 201 and 421 is: 881.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    201 : 421 = 421 : x
  2. Step 2: Convert to fraction form
    201/421 = 421/x
  3. Step 3: Cross multiply
    201x = 421 × 421
  4. Step 4: Simplify right side
    201x = 177,241
  5. Step 5: Solve for x
    x = 177,241/201
  6. Step 6: Final answer
    x = 881.80

Related Problems

Find third proportional to 100.50 and 210.50
Half scale
Find third proportional to 402 and 842
Double scale
Find third proportional to 203 and 425
Similar ratio
Find third proportional to 301.50 and 631.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (2.09) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.