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Finding the Fourth Proportional to 643.80, 965.22 and 319.39

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Solution

The fourth proportional to 643.80, 965.22 and 319.39 is: 478.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.80 : 965.22 = 319.39 : x
  2. Step 2: Convert to fraction form
    643.80/965.22 = 319.39/x
  3. Step 3: Cross multiply
    643.80x = 965.22 × 319.39
  4. Step 4: Simplify right side
    643.80x = 308,283.43
  5. Step 5: Solve for x
    x = 308,283.43/643.80
  6. Step 6: Final answer
    x = 478.85

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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.