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Finding the Fourth Proportional to 404.40, 558.40 and 257.20

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Solution

The fourth proportional to 404.40, 558.40 and 257.20 is: 355.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    404.40 : 558.40 = 257.20 : x
  2. Step 2: Convert to fraction form
    404.40/558.40 = 257.20/x
  3. Step 3: Cross multiply
    404.40x = 558.40 × 257.20
  4. Step 4: Simplify right side
    404.40x = 143,620.48
  5. Step 5: Solve for x
    x = 143,620.48/404.40
  6. Step 6: Final answer
    x = 355.14

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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.