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Finding the Fourth Proportional to 319.60, 479.20 and 103.20

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Solution

The fourth proportional to 319.60, 479.20 and 103.20 is: 154.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    319.60 : 479.20 = 103.20 : x
  2. Step 2: Convert to fraction form
    319.60/479.20 = 103.20/x
  3. Step 3: Cross multiply
    319.60x = 479.20 × 103.20
  4. Step 4: Simplify right side
    319.60x = 49,453.44
  5. Step 5: Solve for x
    x = 49,453.44/319.60
  6. Step 6: Final answer
    x = 154.74

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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.