Home / 390-494

Finding the Third Proportional to 390 and 494

Calculator

Solution

The third proportional to 390 and 494 is: 625.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    390 : 494 = 494 : x
  2. Step 2: Convert to fraction form
    390/494 = 494/x
  3. Step 3: Cross multiply
    390x = 494 × 494
  4. Step 4: Simplify right side
    390x = 244,036
  5. Step 5: Solve for x
    x = 244,036/390
  6. Step 6: Final answer
    x = 625.73

Related Problems

Find third proportional to 195 and 247
Half scale
Find third proportional to 780 and 988
Double scale
Find third proportional to 392 and 497
Similar ratio
Find third proportional to 585 and 741
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.27) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.