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Finding the Fourth Proportional to 643.60, 964.59 and 278.20

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Solution

The fourth proportional to 643.60, 964.59 and 278.20 is: 416.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.60 : 964.59 = 278.20 : x
  2. Step 2: Convert to fraction form
    643.60/964.59 = 278.20/x
  3. Step 3: Cross multiply
    643.60x = 964.59 × 278.20
  4. Step 4: Simplify right side
    643.60x = 268,348.94
  5. Step 5: Solve for x
    x = 268,348.94/643.60
  6. Step 6: Final answer
    x = 416.95

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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.