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Finding the Fourth Proportional to 388.12, 581.58 and 319.72

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Solution

The fourth proportional to 388.12, 581.58 and 319.72 is: 479.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    388.12 : 581.58 = 319.72 : x
  2. Step 2: Convert to fraction form
    388.12/581.58 = 319.72/x
  3. Step 3: Cross multiply
    388.12x = 581.58 × 319.72
  4. Step 4: Simplify right side
    388.12x = 185,942.76
  5. Step 5: Solve for x
    x = 185,942.76/388.12
  6. Step 6: Final answer
    x = 479.09

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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.