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Finding the Fourth Proportional to 645.73, 968.47 and 212.78

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Solution

The fourth proportional to 645.73, 968.47 and 212.78 is: 319.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.73 : 968.47 = 212.78 : x
  2. Step 2: Convert to fraction form
    645.73/968.47 = 212.78/x
  3. Step 3: Cross multiply
    645.73x = 968.47 × 212.78
  4. Step 4: Simplify right side
    645.73x = 206,071.05
  5. Step 5: Solve for x
    x = 206,071.05/645.73
  6. Step 6: Final answer
    x = 319.13

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.