Home / 318.20-439.25-207.79

Finding the Fourth Proportional to 318.20, 439.25 and 207.79

Calculator

Solution

The fourth proportional to 318.20, 439.25 and 207.79 is: 286.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.20 : 439.25 = 207.79 : x
  2. Step 2: Convert to fraction form
    318.20/439.25 = 207.79/x
  3. Step 3: Cross multiply
    318.20x = 439.25 × 207.79
  4. Step 4: Simplify right side
    318.20x = 91,271.76
  5. Step 5: Solve for x
    x = 91,271.76/318.20
  6. Step 6: Final answer
    x = 286.84

Related Problems

Find fourth proportional to 159.10, 219.63 and 103.90
Half scale
Find fourth proportional to 636.40, 878.50 and 415.58
Double scale
Find fourth proportional to 319.20, 440.63 and 208.79
Similar ratio
Find fourth proportional to 477.30, 658.88 and 311.69
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.