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Finding the Fourth Proportional to 643.20, 964.65 and 210.12

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Solution

The fourth proportional to 643.20, 964.65 and 210.12 is: 315.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.20 : 964.65 = 210.12 : x
  2. Step 2: Convert to fraction form
    643.20/964.65 = 210.12/x
  3. Step 3: Cross multiply
    643.20x = 964.65 × 210.12
  4. Step 4: Simplify right side
    643.20x = 202,692.26
  5. Step 5: Solve for x
    x = 202,692.26/643.20
  6. Step 6: Final answer
    x = 315.13

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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.