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Finding the Fourth Proportional to 420.98, 631.20 and 189.83

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Solution

The fourth proportional to 420.98, 631.20 and 189.83 is: 284.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.98 : 631.20 = 189.83 : x
  2. Step 2: Convert to fraction form
    420.98/631.20 = 189.83/x
  3. Step 3: Cross multiply
    420.98x = 631.20 × 189.83
  4. Step 4: Simplify right side
    420.98x = 119,817.54
  5. Step 5: Solve for x
    x = 119,817.54/420.98
  6. Step 6: Final answer
    x = 284.62

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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.