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Finding the Fourth Proportional to 643.60, 965.28 and 210.84

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Solution

The fourth proportional to 643.60, 965.28 and 210.84 is: 316.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.60 : 965.28 = 210.84 : x
  2. Step 2: Convert to fraction form
    643.60/965.28 = 210.84/x
  3. Step 3: Cross multiply
    643.60x = 965.28 × 210.84
  4. Step 4: Simplify right side
    643.60x = 203,519.64
  5. Step 5: Solve for x
    x = 203,519.64/643.60
  6. Step 6: Final answer
    x = 316.22

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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.