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Finding the Fourth Proportional to 685.36, 1,027.36 and 319.84

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Solution

The fourth proportional to 685.36, 1,027.36 and 319.84 is: 479.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.36 : 1,027.36 = 319.84 : x
  2. Step 2: Convert to fraction form
    685.36/1,027.36 = 319.84/x
  3. Step 3: Cross multiply
    685.36x = 1,027.36 × 319.84
  4. Step 4: Simplify right side
    685.36x = 328,590.82
  5. Step 5: Solve for x
    x = 328,590.82/685.36
  6. Step 6: Final answer
    x = 479.44

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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.