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Finding the Fourth Proportional to 643.27, 964.33 and 258.79

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Solution

The fourth proportional to 643.27, 964.33 and 258.79 is: 387.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.27 : 964.33 = 258.79 : x
  2. Step 2: Convert to fraction form
    643.27/964.33 = 258.79/x
  3. Step 3: Cross multiply
    643.27x = 964.33 × 258.79
  4. Step 4: Simplify right side
    643.27x = 249,558.96
  5. Step 5: Solve for x
    x = 249,558.96/643.27
  6. Step 6: Final answer
    x = 387.95

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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.