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Finding the Fourth Proportional to 643.79, 965.01 and 278.75

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Solution

The fourth proportional to 643.79, 965.01 and 278.75 is: 417.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.79 : 965.01 = 278.75 : x
  2. Step 2: Convert to fraction form
    643.79/965.01 = 278.75/x
  3. Step 3: Cross multiply
    643.79x = 965.01 × 278.75
  4. Step 4: Simplify right side
    643.79x = 268,996.54
  5. Step 5: Solve for x
    x = 268,996.54/643.79
  6. Step 6: Final answer
    x = 417.83

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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.