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Finding the Fourth Proportional to 987.28, 1,480.50 and 439.09

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Solution

The fourth proportional to 987.28, 1,480.50 and 439.09 is: 658.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    987.28 : 1,480.50 = 439.09 : x
  2. Step 2: Convert to fraction form
    987.28/1,480.50 = 439.09/x
  3. Step 3: Cross multiply
    987.28x = 1,480.50 × 439.09
  4. Step 4: Simplify right side
    987.28x = 650,072.75
  5. Step 5: Solve for x
    x = 650,072.75/987.28
  6. Step 6: Final answer
    x = 658.45

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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.