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Finding the Fourth Proportional to 998.20, 1,497.30 and 421

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Solution

The fourth proportional to 998.20, 1,497.30 and 421 is: 631.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    998.20 : 1,497.30 = 421 : x
  2. Step 2: Convert to fraction form
    998.20/1,497.30 = 421/x
  3. Step 3: Cross multiply
    998.20x = 1,497.30 × 421
  4. Step 4: Simplify right side
    998.20x = 630,363.30
  5. Step 5: Solve for x
    x = 630,363.30/998.20
  6. Step 6: Final answer
    x = 631.50

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Double scale
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Similar ratio
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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.