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Finding the Fourth Proportional to 971.72, 1,459.20 and 638.72

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Solution

The fourth proportional to 971.72, 1,459.20 and 638.72 is: 959.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    971.72 : 1,459.20 = 638.72 : x
  2. Step 2: Convert to fraction form
    971.72/1,459.20 = 638.72/x
  3. Step 3: Cross multiply
    971.72x = 1,459.20 × 638.72
  4. Step 4: Simplify right side
    971.72x = 932,009.73
  5. Step 5: Solve for x
    x = 932,009.73/971.72
  6. Step 6: Final answer
    x = 959.14

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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.