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Finding the Fourth Proportional to 253.20, 381.28 and 221.08

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Solution

The fourth proportional to 253.20, 381.28 and 221.08 is: 332.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    253.20 : 381.28 = 221.08 : x
  2. Step 2: Convert to fraction form
    253.20/381.28 = 221.08/x
  3. Step 3: Cross multiply
    253.20x = 381.28 × 221.08
  4. Step 4: Simplify right side
    253.20x = 84,293.38
  5. Step 5: Solve for x
    x = 84,293.38/253.20
  6. Step 6: Final answer
    x = 332.91

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.