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Finding the Fourth Proportional to 643.14, 964.31 and 210.20

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Solution

The fourth proportional to 643.14, 964.31 and 210.20 is: 315.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.14 : 964.31 = 210.20 : x
  2. Step 2: Convert to fraction form
    643.14/964.31 = 210.20/x
  3. Step 3: Cross multiply
    643.14x = 964.31 × 210.20
  4. Step 4: Simplify right side
    643.14x = 202,692.09
  5. Step 5: Solve for x
    x = 202,692.09/643.14
  6. Step 6: Final answer
    x = 315.16

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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.