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Finding the Fourth Proportional to 257.76, 386.88 and 217.44

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Solution

The fourth proportional to 257.76, 386.88 and 217.44 is: 326.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    257.76 : 386.88 = 217.44 : x
  2. Step 2: Convert to fraction form
    257.76/386.88 = 217.44/x
  3. Step 3: Cross multiply
    257.76x = 386.88 × 217.44
  4. Step 4: Simplify right side
    257.76x = 84,123.19
  5. Step 5: Solve for x
    x = 84,123.19/257.76
  6. Step 6: Final answer
    x = 326.36

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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.