Home / 439.80-606.20-308.58

Finding the Fourth Proportional to 439.80, 606.20 and 308.58

Calculator

Solution

The fourth proportional to 439.80, 606.20 and 308.58 is: 425.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    439.80 : 606.20 = 308.58 : x
  2. Step 2: Convert to fraction form
    439.80/606.20 = 308.58/x
  3. Step 3: Cross multiply
    439.80x = 606.20 × 308.58
  4. Step 4: Simplify right side
    439.80x = 187,059.65
  5. Step 5: Solve for x
    x = 187,059.65/439.80
  6. Step 6: Final answer
    x = 425.33

Related Problems

Find fourth proportional to 219.90, 303.10 and 154.29
Half scale
Find fourth proportional to 879.60, 1,212.39 and 617.16
Double scale
Find fourth proportional to 440.80, 607.57 and 309.58
Similar ratio
Find fourth proportional to 659.70, 909.29 and 462.87
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.