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Finding the Fourth Proportional to 643.28, 965.01 and 258.50

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Solution

The fourth proportional to 643.28, 965.01 and 258.50 is: 387.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.28 : 965.01 = 258.50 : x
  2. Step 2: Convert to fraction form
    643.28/965.01 = 258.50/x
  3. Step 3: Cross multiply
    643.28x = 965.01 × 258.50
  4. Step 4: Simplify right side
    643.28x = 249,455.09
  5. Step 5: Solve for x
    x = 249,455.09/643.28
  6. Step 6: Final answer
    x = 387.79

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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.