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Finding the Fourth Proportional to 521.81, 720.09 and 285.75

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Solution

The fourth proportional to 521.81, 720.09 and 285.75 is: 394.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.81 : 720.09 = 285.75 : x
  2. Step 2: Convert to fraction form
    521.81/720.09 = 285.75/x
  3. Step 3: Cross multiply
    521.81x = 720.09 × 285.75
  4. Step 4: Simplify right side
    521.81x = 205,764.91
  5. Step 5: Solve for x
    x = 205,764.91/521.81
  6. Step 6: Final answer
    x = 394.33

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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.