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Finding the Fourth Proportional to 355.28, 490.29 and 215.42

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Solution

The fourth proportional to 355.28, 490.29 and 215.42 is: 297.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    355.28 : 490.29 = 215.42 : x
  2. Step 2: Convert to fraction form
    355.28/490.29 = 215.42/x
  3. Step 3: Cross multiply
    355.28x = 490.29 × 215.42
  4. Step 4: Simplify right side
    355.28x = 105,618.27
  5. Step 5: Solve for x
    x = 105,618.27/355.28
  6. Step 6: Final answer
    x = 297.28

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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.