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Finding the Fourth Proportional to 257.18, 386.30 and 218.73

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Solution

The fourth proportional to 257.18, 386.30 and 218.73 is: 328.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    257.18 : 386.30 = 218.73 : x
  2. Step 2: Convert to fraction form
    257.18/386.30 = 218.73/x
  3. Step 3: Cross multiply
    257.18x = 386.30 × 218.73
  4. Step 4: Simplify right side
    257.18x = 84,495.40
  5. Step 5: Solve for x
    x = 84,495.40/257.18
  6. Step 6: Final answer
    x = 328.55

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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.