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Finding the Fourth Proportional to 309.21, 425.97 and 215.79

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Solution

The fourth proportional to 309.21, 425.97 and 215.79 is: 297.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    309.21 : 425.97 = 215.79 : x
  2. Step 2: Convert to fraction form
    309.21/425.97 = 215.79/x
  3. Step 3: Cross multiply
    309.21x = 425.97 × 215.79
  4. Step 4: Simplify right side
    309.21x = 91,918.47
  5. Step 5: Solve for x
    x = 91,918.47/309.21
  6. Step 6: Final answer
    x = 297.27

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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.