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Finding the Fourth Proportional to 643.89, 965.97 and 319.22

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Solution

The fourth proportional to 643.89, 965.97 and 319.22 is: 478.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.89 : 965.97 = 319.22 : x
  2. Step 2: Convert to fraction form
    643.89/965.97 = 319.22/x
  3. Step 3: Cross multiply
    643.89x = 965.97 × 319.22
  4. Step 4: Simplify right side
    643.89x = 308,352.11
  5. Step 5: Solve for x
    x = 308,352.11/643.89
  6. Step 6: Final answer
    x = 478.89

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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.