Home / 422.90-579.86-381.28

Finding the Fourth Proportional to 422.90, 579.86 and 381.28

Calculator

Solution

The fourth proportional to 422.90, 579.86 and 381.28 is: 522.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    422.90 : 579.86 = 381.28 : x
  2. Step 2: Convert to fraction form
    422.90/579.86 = 381.28/x
  3. Step 3: Cross multiply
    422.90x = 579.86 × 381.28
  4. Step 4: Simplify right side
    422.90x = 221,089.02
  5. Step 5: Solve for x
    x = 221,089.02/422.90
  6. Step 6: Final answer
    x = 522.79

Related Problems

Find fourth proportional to 211.45, 289.93 and 190.64
Half scale
Find fourth proportional to 845.80, 1,159.72 and 762.56
Double scale
Find fourth proportional to 423.90, 581.23 and 382.28
Similar ratio
Find fourth proportional to 634.35, 869.79 and 571.92
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.