Home / 257.81-399.75

Finding the Third Proportional to 257.81 and 399.75

Calculator

Solution

The third proportional to 257.81 and 399.75 is: 619.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    257.81 : 399.75 = 399.75 : x
  2. Step 2: Convert to fraction form
    257.81/399.75 = 399.75/x
  3. Step 3: Cross multiply
    257.81x = 399.75 × 399.75
  4. Step 4: Simplify right side
    257.81x = 159,800.06
  5. Step 5: Solve for x
    x = 159,800.06/257.81
  6. Step 6: Final answer
    x = 619.83

Related Problems

Find third proportional to 128.91 and 199.88
Half scale
Find third proportional to 515.63 and 799.50
Double scale
Find third proportional to 260 and 403
Similar ratio
Find third proportional to 386.72 and 599.63
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.55) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.