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Finding the Fourth Proportional to 987.64, 1,481.10 and 439.72

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Solution

The fourth proportional to 987.64, 1,481.10 and 439.72 is: 659.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    987.64 : 1,481.10 = 439.72 : x
  2. Step 2: Convert to fraction form
    987.64/1,481.10 = 439.72/x
  3. Step 3: Cross multiply
    987.64x = 1,481.10 × 439.72
  4. Step 4: Simplify right side
    987.64x = 651,269.29
  5. Step 5: Solve for x
    x = 651,269.29/987.64
  6. Step 6: Final answer
    x = 659.42

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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.