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Finding the Fourth Proportional to 643.87, 964.95 and 278.56

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Solution

The fourth proportional to 643.87, 964.95 and 278.56 is: 417.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.87 : 964.95 = 278.56 : x
  2. Step 2: Convert to fraction form
    643.87/964.95 = 278.56/x
  3. Step 3: Cross multiply
    643.87x = 964.95 × 278.56
  4. Step 4: Simplify right side
    643.87x = 268,796.47
  5. Step 5: Solve for x
    x = 268,796.47/643.87
  6. Step 6: Final answer
    x = 417.47

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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.