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Finding the Fourth Proportional to 643.36, 965.12 and 210.56

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Solution

The fourth proportional to 643.36, 965.12 and 210.56 is: 315.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.36 : 965.12 = 210.56 : x
  2. Step 2: Convert to fraction form
    643.36/965.12 = 210.56/x
  3. Step 3: Cross multiply
    643.36x = 965.12 × 210.56
  4. Step 4: Simplify right side
    643.36x = 203,215.67
  5. Step 5: Solve for x
    x = 203,215.67/643.36
  6. Step 6: Final answer
    x = 315.87

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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.