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Finding the Fourth Proportional to 643.56, 965.31 and 210.72

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Solution

The fourth proportional to 643.56, 965.31 and 210.72 is: 316.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.56 : 965.31 = 210.72 : x
  2. Step 2: Convert to fraction form
    643.56/965.31 = 210.72/x
  3. Step 3: Cross multiply
    643.56x = 965.31 × 210.72
  4. Step 4: Simplify right side
    643.56x = 203,410.12
  5. Step 5: Solve for x
    x = 203,410.12/643.56
  6. Step 6: Final answer
    x = 316.07

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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.