Home / 345-380

Finding the Third Proportional to 345 and 380

Calculator

Solution

The third proportional to 345 and 380 is: 418.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    345 : 380 = 380 : x
  2. Step 2: Convert to fraction form
    345/380 = 380/x
  3. Step 3: Cross multiply
    345x = 380 × 380
  4. Step 4: Simplify right side
    345x = 144,400
  5. Step 5: Solve for x
    x = 144,400/345
  6. Step 6: Final answer
    x = 418.55

Related Problems

Find third proportional to 172.50 and 190
Half scale
Find third proportional to 690 and 760
Double scale
Find third proportional to 347 and 382
Similar ratio
Find third proportional to 517.50 and 570
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.10) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.