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Finding the Fourth Proportional to 319.78, 479.72 and 103.38

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Solution

The fourth proportional to 319.78, 479.72 and 103.38 is: 155.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    319.78 : 479.72 = 103.38 : x
  2. Step 2: Convert to fraction form
    319.78/479.72 = 103.38/x
  3. Step 3: Cross multiply
    319.78x = 479.72 × 103.38
  4. Step 4: Simplify right side
    319.78x = 49,593.45
  5. Step 5: Solve for x
    x = 49,593.45/319.78
  6. Step 6: Final answer
    x = 155.09

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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.