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Finding the Fourth Proportional to 479.71, 721.19 and 428.68

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Solution

The fourth proportional to 479.71, 721.19 and 428.68 is: 644.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    479.71 : 721.19 = 428.68 : x
  2. Step 2: Convert to fraction form
    479.71/721.19 = 428.68/x
  3. Step 3: Cross multiply
    479.71x = 721.19 × 428.68
  4. Step 4: Simplify right side
    479.71x = 309,159.73
  5. Step 5: Solve for x
    x = 309,159.73/479.71
  6. Step 6: Final answer
    x = 644.47

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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.