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Finding the Fourth Proportional to 387.85, 581.91 and 205.12

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Solution

The fourth proportional to 387.85, 581.91 and 205.12 is: 307.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.85 : 581.91 = 205.12 : x
  2. Step 2: Convert to fraction form
    387.85/581.91 = 205.12/x
  3. Step 3: Cross multiply
    387.85x = 581.91 × 205.12
  4. Step 4: Simplify right side
    387.85x = 119,361.38
  5. Step 5: Solve for x
    x = 119,361.38/387.85
  6. Step 6: Final answer
    x = 307.75

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.