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Finding the Fourth Proportional to 215.09, 320.57 and 213.30

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Solution

The fourth proportional to 215.09, 320.57 and 213.30 is: 317.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    215.09 : 320.57 = 213.30 : x
  2. Step 2: Convert to fraction form
    215.09/320.57 = 213.30/x
  3. Step 3: Cross multiply
    215.09x = 320.57 × 213.30
  4. Step 4: Simplify right side
    215.09x = 68,377.58
  5. Step 5: Solve for x
    x = 68,377.58/215.09
  6. Step 6: Final answer
    x = 317.90

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.