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Finding the Fourth Proportional to 279.20, 417.26 and 257.31

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Solution

The fourth proportional to 279.20, 417.26 and 257.31 is: 384.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.20 : 417.26 = 257.31 : x
  2. Step 2: Convert to fraction form
    279.20/417.26 = 257.31/x
  3. Step 3: Cross multiply
    279.20x = 417.26 × 257.31
  4. Step 4: Simplify right side
    279.20x = 107,365.17
  5. Step 5: Solve for x
    x = 107,365.17/279.20
  6. Step 6: Final answer
    x = 384.55

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.