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Finding the Fourth Proportional to 447.60, 618 and 398.40

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Solution

The fourth proportional to 447.60, 618 and 398.40 is: 550.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    447.60 : 618 = 398.40 : x
  2. Step 2: Convert to fraction form
    447.60/618 = 398.40/x
  3. Step 3: Cross multiply
    447.60x = 618 × 398.40
  4. Step 4: Simplify right side
    447.60x = 246,211.20
  5. Step 5: Solve for x
    x = 246,211.20/447.60
  6. Step 6: Final answer
    x = 550.07

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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.