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Finding the Fourth Proportional to 456.38, 681.21 and 419.78

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Solution

The fourth proportional to 456.38, 681.21 and 419.78 is: 626.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    456.38 : 681.21 = 419.78 : x
  2. Step 2: Convert to fraction form
    456.38/681.21 = 419.78/x
  3. Step 3: Cross multiply
    456.38x = 681.21 × 419.78
  4. Step 4: Simplify right side
    456.38x = 285,960.04
  5. Step 5: Solve for x
    x = 285,960.04/456.38
  6. Step 6: Final answer
    x = 626.58

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.