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Finding the Fourth Proportional to 685.29, 1,027.77 and 319.89

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Solution

The fourth proportional to 685.29, 1,027.77 and 319.89 is: 479.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.29 : 1,027.77 = 319.89 : x
  2. Step 2: Convert to fraction form
    685.29/1,027.77 = 319.89/x
  3. Step 3: Cross multiply
    685.29x = 1,027.77 × 319.89
  4. Step 4: Simplify right side
    685.29x = 328,773.35
  5. Step 5: Solve for x
    x = 328,773.35/685.29
  6. Step 6: Final answer
    x = 479.76

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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.