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Finding the Fourth Proportional to 643.67, 965.20 and 318.66

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Solution

The fourth proportional to 643.67, 965.20 and 318.66 is: 477.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.67 : 965.20 = 318.66 : x
  2. Step 2: Convert to fraction form
    643.67/965.20 = 318.66/x
  3. Step 3: Cross multiply
    643.67x = 965.20 × 318.66
  4. Step 4: Simplify right side
    643.67x = 307,570.63
  5. Step 5: Solve for x
    x = 307,570.63/643.67
  6. Step 6: Final answer
    x = 477.84

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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.