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Finding the Fourth Proportional to 212.18, 319.91 and 209.88

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Solution

The fourth proportional to 212.18, 319.91 and 209.88 is: 316.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.18 : 319.91 = 209.88 : x
  2. Step 2: Convert to fraction form
    212.18/319.91 = 209.88/x
  3. Step 3: Cross multiply
    212.18x = 319.91 × 209.88
  4. Step 4: Simplify right side
    212.18x = 67,141.66
  5. Step 5: Solve for x
    x = 67,141.66/212.18
  6. Step 6: Final answer
    x = 316.44

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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.