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Finding the Fourth Proportional to 643.58, 965.41 and 210.78

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Solution

The fourth proportional to 643.58, 965.41 and 210.78 is: 316.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.58 : 965.41 = 210.78 : x
  2. Step 2: Convert to fraction form
    643.58/965.41 = 210.78/x
  3. Step 3: Cross multiply
    643.58x = 965.41 × 210.78
  4. Step 4: Simplify right side
    643.58x = 203,489.12
  5. Step 5: Solve for x
    x = 203,489.12/643.58
  6. Step 6: Final answer
    x = 316.18

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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.