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Finding the Fourth Proportional to 643.38, 965.11 and 258.63

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Solution

The fourth proportional to 643.38, 965.11 and 258.63 is: 387.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.38 : 965.11 = 258.63 : x
  2. Step 2: Convert to fraction form
    643.38/965.11 = 258.63/x
  3. Step 3: Cross multiply
    643.38x = 965.11 × 258.63
  4. Step 4: Simplify right side
    643.38x = 249,606.40
  5. Step 5: Solve for x
    x = 249,606.40/643.38
  6. Step 6: Final answer
    x = 387.96

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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.