Home / 243-396

Finding the Third Proportional to 243 and 396

Calculator

Solution

The third proportional to 243 and 396 is: 645.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    243 : 396 = 396 : x
  2. Step 2: Convert to fraction form
    243/396 = 396/x
  3. Step 3: Cross multiply
    243x = 396 × 396
  4. Step 4: Simplify right side
    243x = 156,816
  5. Step 5: Solve for x
    x = 156,816/243
  6. Step 6: Final answer
    x = 645.33

Related Problems

Find third proportional to 121.50 and 198
Half scale
Find third proportional to 486 and 792
Double scale
Find third proportional to 245 and 399
Similar ratio
Find third proportional to 364.50 and 594
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.63) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.