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Finding the Fourth Proportional to 387.81, 582.25 and 257.90

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Solution

The fourth proportional to 387.81, 582.25 and 257.90 is: 387.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.81 : 582.25 = 257.90 : x
  2. Step 2: Convert to fraction form
    387.81/582.25 = 257.90/x
  3. Step 3: Cross multiply
    387.81x = 582.25 × 257.90
  4. Step 4: Simplify right side
    387.81x = 150,160.38
  5. Step 5: Solve for x
    x = 150,160.38/387.81
  6. Step 6: Final answer
    x = 387.20

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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.