Home / 439.06-659.31-420.34

Finding the Fourth Proportional to 439.06, 659.31 and 420.34

Calculator

Solution

The fourth proportional to 439.06, 659.31 and 420.34 is: 631.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    439.06 : 659.31 = 420.34 : x
  2. Step 2: Convert to fraction form
    439.06/659.31 = 420.34/x
  3. Step 3: Cross multiply
    439.06x = 659.31 × 420.34
  4. Step 4: Simplify right side
    439.06x = 277,134.37
  5. Step 5: Solve for x
    x = 277,134.37/439.06
  6. Step 6: Final answer
    x = 631.20

Related Problems

Find fourth proportional to 219.53, 329.66 and 210.17
Half scale
Find fourth proportional to 878.12, 1,318.62 and 840.68
Double scale
Find fourth proportional to 440.06, 660.81 and 421.34
Similar ratio
Find fourth proportional to 658.59, 988.97 and 630.51
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.