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Finding the Fourth Proportional to 643.89, 965.00 and 258.69

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Solution

The fourth proportional to 643.89, 965.00 and 258.69 is: 387.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.89 : 965.00 = 258.69 : x
  2. Step 2: Convert to fraction form
    643.89/965.00 = 258.69/x
  3. Step 3: Cross multiply
    643.89x = 965.00 × 258.69
  4. Step 4: Simplify right side
    643.89x = 249,634.56
  5. Step 5: Solve for x
    x = 249,634.56/643.89
  6. Step 6: Final answer
    x = 387.70

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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.