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Finding the Fourth Proportional to 387.86, 581.90 and 205.11

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Solution

The fourth proportional to 387.86, 581.90 and 205.11 is: 307.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.86 : 581.90 = 205.11 : x
  2. Step 2: Convert to fraction form
    387.86/581.90 = 205.11/x
  3. Step 3: Cross multiply
    387.86x = 581.90 × 205.11
  4. Step 4: Simplify right side
    387.86x = 119,352.48
  5. Step 5: Solve for x
    x = 119,352.48/387.86
  6. Step 6: Final answer
    x = 307.72

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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.