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Finding the Fourth Proportional to 1,638.68, 2,459.05 and 664.78

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Solution

The fourth proportional to 1,638.68, 2,459.05 and 664.78 is: 997.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,638.68 : 2,459.05 = 664.78 : x
  2. Step 2: Convert to fraction form
    1,638.68/2,459.05 = 664.78/x
  3. Step 3: Cross multiply
    1,638.68x = 2,459.05 × 664.78
  4. Step 4: Simplify right side
    1,638.68x = 1,634,730.04
  5. Step 5: Solve for x
    x = 1,634,730.04/1,638.68
  6. Step 6: Final answer
    x = 997.59

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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.