Home / 298.50-390

Finding the Third Proportional to 298.50 and 390

Calculator

Solution

The third proportional to 298.50 and 390 is: 509.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    298.50 : 390 = 390 : x
  2. Step 2: Convert to fraction form
    298.50/390 = 390/x
  3. Step 3: Cross multiply
    298.50x = 390 × 390
  4. Step 4: Simplify right side
    298.50x = 152,100
  5. Step 5: Solve for x
    x = 152,100/298.50
  6. Step 6: Final answer
    x = 509.55

Related Problems

Find third proportional to 149.25 and 195
Half scale
Find third proportional to 597 and 780
Double scale
Find third proportional to 301 and 393
Similar ratio
Find third proportional to 447.75 and 585
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.31) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.