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Finding the Fourth Proportional to 328.20, 453.78 and 287.20

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Solution

The fourth proportional to 328.20, 453.78 and 287.20 is: 397.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    328.20 : 453.78 = 287.20 : x
  2. Step 2: Convert to fraction form
    328.20/453.78 = 287.20/x
  3. Step 3: Cross multiply
    328.20x = 453.78 × 287.20
  4. Step 4: Simplify right side
    328.20x = 130,325.62
  5. Step 5: Solve for x
    x = 130,325.62/328.20
  6. Step 6: Final answer
    x = 397.09

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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.