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Finding the Fourth Proportional to 645.72, 968.18 and 212.76

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Solution

The fourth proportional to 645.72, 968.18 and 212.76 is: 319.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.72 : 968.18 = 212.76 : x
  2. Step 2: Convert to fraction form
    645.72/968.18 = 212.76/x
  3. Step 3: Cross multiply
    645.72x = 968.18 × 212.76
  4. Step 4: Simplify right side
    645.72x = 205,989.98
  5. Step 5: Solve for x
    x = 205,989.98/645.72
  6. Step 6: Final answer
    x = 319.01

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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.