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Finding the Fourth Proportional to 328.80, 490.20 and 320.39

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Solution

The fourth proportional to 328.80, 490.20 and 320.39 is: 477.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    328.80 : 490.20 = 320.39 : x
  2. Step 2: Convert to fraction form
    328.80/490.20 = 320.39/x
  3. Step 3: Cross multiply
    328.80x = 490.20 × 320.39
  4. Step 4: Simplify right side
    328.80x = 157,052.73
  5. Step 5: Solve for x
    x = 157,052.73/328.80
  6. Step 6: Final answer
    x = 477.65

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.