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Finding the Fourth Proportional to 989.82, 1,484.72 and 405.09

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Solution

The fourth proportional to 989.82, 1,484.72 and 405.09 is: 607.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    989.82 : 1,484.72 = 405.09 : x
  2. Step 2: Convert to fraction form
    989.82/1,484.72 = 405.09/x
  3. Step 3: Cross multiply
    989.82x = 1,484.72 × 405.09
  4. Step 4: Simplify right side
    989.82x = 601,445.22
  5. Step 5: Solve for x
    x = 601,445.22/989.82
  6. Step 6: Final answer
    x = 607.63

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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.