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Finding the Fourth Proportional to 427.39, 641.12 and 319.86

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Solution

The fourth proportional to 427.39, 641.12 and 319.86 is: 479.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.39 : 641.12 = 319.86 : x
  2. Step 2: Convert to fraction form
    427.39/641.12 = 319.86/x
  3. Step 3: Cross multiply
    427.39x = 641.12 × 319.86
  4. Step 4: Simplify right side
    427.39x = 205,068.64
  5. Step 5: Solve for x
    x = 205,068.64/427.39
  6. Step 6: Final answer
    x = 479.82

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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.