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Finding the Fourth Proportional to 387.32, 581.18 and 257.45

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Solution

The fourth proportional to 387.32, 581.18 and 257.45 is: 386.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.32 : 581.18 = 257.45 : x
  2. Step 2: Convert to fraction form
    387.32/581.18 = 257.45/x
  3. Step 3: Cross multiply
    387.32x = 581.18 × 257.45
  4. Step 4: Simplify right side
    387.32x = 149,620.60
  5. Step 5: Solve for x
    x = 149,620.60/387.32
  6. Step 6: Final answer
    x = 386.30

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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.