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Finding the Fourth Proportional to 443.20, 611.28 and 285.72

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Solution

The fourth proportional to 443.20, 611.28 and 285.72 is: 394.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    443.20 : 611.28 = 285.72 : x
  2. Step 2: Convert to fraction form
    443.20/611.28 = 285.72/x
  3. Step 3: Cross multiply
    443.20x = 611.28 × 285.72
  4. Step 4: Simplify right side
    443.20x = 174,654.92
  5. Step 5: Solve for x
    x = 174,654.92/443.20
  6. Step 6: Final answer
    x = 394.08

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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.