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Finding the Fourth Proportional to 643.72, 965.34 and 319.24

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Solution

The fourth proportional to 643.72, 965.34 and 319.24 is: 478.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.72 : 965.34 = 319.24 : x
  2. Step 2: Convert to fraction form
    643.72/965.34 = 319.24/x
  3. Step 3: Cross multiply
    643.72x = 965.34 × 319.24
  4. Step 4: Simplify right side
    643.72x = 308,175.14
  5. Step 5: Solve for x
    x = 308,175.14/643.72
  6. Step 6: Final answer
    x = 478.74

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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.