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Finding the Fourth Proportional to 212.28, 315.72 and 211.56

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Solution

The fourth proportional to 212.28, 315.72 and 211.56 is: 314.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    212.28 : 315.72 = 211.56 : x
  2. Step 2: Convert to fraction form
    212.28/315.72 = 211.56/x
  3. Step 3: Cross multiply
    212.28x = 315.72 × 211.56
  4. Step 4: Simplify right side
    212.28x = 66,793.72
  5. Step 5: Solve for x
    x = 66,793.72/212.28
  6. Step 6: Final answer
    x = 314.65

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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.