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Finding the Fourth Proportional to 871.40, 1,305.28 and 654.68

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Solution

The fourth proportional to 871.40, 1,305.28 and 654.68 is: 980.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    871.40 : 1,305.28 = 654.68 : x
  2. Step 2: Convert to fraction form
    871.40/1,305.28 = 654.68/x
  3. Step 3: Cross multiply
    871.40x = 1,305.28 × 654.68
  4. Step 4: Simplify right side
    871.40x = 854,540.71
  5. Step 5: Solve for x
    x = 854,540.71/871.40
  6. Step 6: Final answer
    x = 980.65

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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.