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Finding the Fourth Proportional to 339.12, 508.38 and 257.76

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Solution

The fourth proportional to 339.12, 508.38 and 257.76 is: 386.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    339.12 : 508.38 = 257.76 : x
  2. Step 2: Convert to fraction form
    339.12/508.38 = 257.76/x
  3. Step 3: Cross multiply
    339.12x = 508.38 × 257.76
  4. Step 4: Simplify right side
    339.12x = 131,040.03
  5. Step 5: Solve for x
    x = 131,040.03/339.12
  6. Step 6: Final answer
    x = 386.41

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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.