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Finding the Fourth Proportional to 643.66, 965.85 and 319.03

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Solution

The fourth proportional to 643.66, 965.85 and 319.03 is: 478.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.66 : 965.85 = 319.03 : x
  2. Step 2: Convert to fraction form
    643.66/965.85 = 319.03/x
  3. Step 3: Cross multiply
    643.66x = 965.85 × 319.03
  4. Step 4: Simplify right side
    643.66x = 308,135.13
  5. Step 5: Solve for x
    x = 308,135.13/643.66
  6. Step 6: Final answer
    x = 478.72

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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.