Home / 199-391

Finding the Third Proportional to 199 and 391

Calculator

Solution

The third proportional to 199 and 391 is: 768.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    199 : 391 = 391 : x
  2. Step 2: Convert to fraction form
    199/391 = 391/x
  3. Step 3: Cross multiply
    199x = 391 × 391
  4. Step 4: Simplify right side
    199x = 152,881
  5. Step 5: Solve for x
    x = 152,881/199
  6. Step 6: Final answer
    x = 768.25

Related Problems

Find third proportional to 99.50 and 195.50
Half scale
Find third proportional to 398 and 782
Double scale
Find third proportional to 201 and 395
Similar ratio
Find third proportional to 298.50 and 586.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.96) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.