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Finding the Fourth Proportional to 643.56, 965.48 and 210.76

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Solution

The fourth proportional to 643.56, 965.48 and 210.76 is: 316.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.56 : 965.48 = 210.76 : x
  2. Step 2: Convert to fraction form
    643.56/965.48 = 210.76/x
  3. Step 3: Cross multiply
    643.56x = 965.48 × 210.76
  4. Step 4: Simplify right side
    643.56x = 203,484.56
  5. Step 5: Solve for x
    x = 203,484.56/643.56
  6. Step 6: Final answer
    x = 316.19

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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.