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Finding the Fourth Proportional to 211.89, 315.91 and 206.56

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Solution

The fourth proportional to 211.89, 315.91 and 206.56 is: 307.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    211.89 : 315.91 = 206.56 : x
  2. Step 2: Convert to fraction form
    211.89/315.91 = 206.56/x
  3. Step 3: Cross multiply
    211.89x = 315.91 × 206.56
  4. Step 4: Simplify right side
    211.89x = 65,251.76
  5. Step 5: Solve for x
    x = 65,251.76/211.89
  6. Step 6: Final answer
    x = 307.95

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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.