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Finding the Fourth Proportional to 1,638.70, 2,456.43 and 664.30

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Solution

The fourth proportional to 1,638.70, 2,456.43 and 664.30 is: 995.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,638.70 : 2,456.43 = 664.30 : x
  2. Step 2: Convert to fraction form
    1,638.70/2,456.43 = 664.30/x
  3. Step 3: Cross multiply
    1,638.70x = 2,456.43 × 664.30
  4. Step 4: Simplify right side
    1,638.70x = 1,631,806.45
  5. Step 5: Solve for x
    x = 1,631,806.45/1,638.70
  6. Step 6: Final answer
    x = 995.79

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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.