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Finding the Fourth Proportional to 643.60, 965.32 and 210.80

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Solution

The fourth proportional to 643.60, 965.32 and 210.80 is: 316.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.60 : 965.32 = 210.80 : x
  2. Step 2: Convert to fraction form
    643.60/965.32 = 210.80/x
  3. Step 3: Cross multiply
    643.60x = 965.32 × 210.80
  4. Step 4: Simplify right side
    643.60x = 203,489.46
  5. Step 5: Solve for x
    x = 203,489.46/643.60
  6. Step 6: Final answer
    x = 316.17

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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.