Home / 275-391

Finding the Third Proportional to 275 and 391

Calculator

Solution

The third proportional to 275 and 391 is: 555.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    275 : 391 = 391 : x
  2. Step 2: Convert to fraction form
    275/391 = 391/x
  3. Step 3: Cross multiply
    275x = 391 × 391
  4. Step 4: Simplify right side
    275x = 152,881
  5. Step 5: Solve for x
    x = 152,881/275
  6. Step 6: Final answer
    x = 555.93

Related Problems

Find third proportional to 137.50 and 195.50
Half scale
Find third proportional to 550 and 782
Double scale
Find third proportional to 277 and 394
Similar ratio
Find third proportional to 412.50 and 586.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.42) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.