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Finding the Fourth Proportional to 387.86, 581.29 and 205.21

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Solution

The fourth proportional to 387.86, 581.29 and 205.21 is: 307.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.86 : 581.29 = 205.21 : x
  2. Step 2: Convert to fraction form
    387.86/581.29 = 205.21/x
  3. Step 3: Cross multiply
    387.86x = 581.29 × 205.21
  4. Step 4: Simplify right side
    387.86x = 119,284.55
  5. Step 5: Solve for x
    x = 119,284.55/387.86
  6. Step 6: Final answer
    x = 307.54

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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.