Home / 340-387

Finding the Third Proportional to 340 and 387

Calculator

Solution

The third proportional to 340 and 387 is: 440.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    340 : 387 = 387 : x
  2. Step 2: Convert to fraction form
    340/387 = 387/x
  3. Step 3: Cross multiply
    340x = 387 × 387
  4. Step 4: Simplify right side
    340x = 149,769
  5. Step 5: Solve for x
    x = 149,769/340
  6. Step 6: Final answer
    x = 440.50

Related Problems

Find third proportional to 170 and 193.50
Half scale
Find third proportional to 680 and 774
Double scale
Find third proportional to 342 and 389
Similar ratio
Find third proportional to 510 and 580.50
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.14) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.