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Finding the Fourth Proportional to 257.28, 354.30 and 219.90

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Solution

The fourth proportional to 257.28, 354.30 and 219.90 is: 302.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    257.28 : 354.30 = 219.90 : x
  2. Step 2: Convert to fraction form
    257.28/354.30 = 219.90/x
  3. Step 3: Cross multiply
    257.28x = 354.30 × 219.90
  4. Step 4: Simplify right side
    257.28x = 77,910.57
  5. Step 5: Solve for x
    x = 77,910.57/257.28
  6. Step 6: Final answer
    x = 302.82

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.