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Finding the Fourth Proportional to 420.78, 631.17 and 283.49

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Solution

The fourth proportional to 420.78, 631.17 and 283.49 is: 425.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.78 : 631.17 = 283.49 : x
  2. Step 2: Convert to fraction form
    420.78/631.17 = 283.49/x
  3. Step 3: Cross multiply
    420.78x = 631.17 × 283.49
  4. Step 4: Simplify right side
    420.78x = 178,930.38
  5. Step 5: Solve for x
    x = 178,930.38/420.78
  6. Step 6: Final answer
    x = 425.24

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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.