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Finding the Fourth Proportional to 980.72, 1,353.24 and 631.28

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Solution

The fourth proportional to 980.72, 1,353.24 and 631.28 is: 871.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    980.72 : 1,353.24 = 631.28 : x
  2. Step 2: Convert to fraction form
    980.72/1,353.24 = 631.28/x
  3. Step 3: Cross multiply
    980.72x = 1,353.24 × 631.28
  4. Step 4: Simplify right side
    980.72x = 854,273.35
  5. Step 5: Solve for x
    x = 854,273.35/980.72
  6. Step 6: Final answer
    x = 871.07

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.