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Finding the Fourth Proportional to 871.56, 1,306.64 and 689.76

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Solution

The fourth proportional to 871.56, 1,306.64 and 689.76 is: 1,034.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    871.56 : 1,306.64 = 689.76 : x
  2. Step 2: Convert to fraction form
    871.56/1,306.64 = 689.76/x
  3. Step 3: Cross multiply
    871.56x = 1,306.64 × 689.76
  4. Step 4: Simplify right side
    871.56x = 901,269.73
  5. Step 5: Solve for x
    x = 901,269.73/871.56
  6. Step 6: Final answer
    x = 1,034.09

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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.