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Finding the Fourth Proportional to 643.82, 964.76 and 278.42

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Solution

The fourth proportional to 643.82, 964.76 and 278.42 is: 417.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.82 : 964.76 = 278.42 : x
  2. Step 2: Convert to fraction form
    643.82/964.76 = 278.42/x
  3. Step 3: Cross multiply
    643.82x = 964.76 × 278.42
  4. Step 4: Simplify right side
    643.82x = 268,602.26
  5. Step 5: Solve for x
    x = 268,602.26/643.82
  6. Step 6: Final answer
    x = 417.20

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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.