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Finding the Fourth Proportional to 643.42, 965.21 and 210.58

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Solution

The fourth proportional to 643.42, 965.21 and 210.58 is: 315.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.42 : 965.21 = 210.58 : x
  2. Step 2: Convert to fraction form
    643.42/965.21 = 210.58/x
  3. Step 3: Cross multiply
    643.42x = 965.21 × 210.58
  4. Step 4: Simplify right side
    643.42x = 203,253.92
  5. Step 5: Solve for x
    x = 203,253.92/643.42
  6. Step 6: Final answer
    x = 315.90

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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.