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Finding the Fourth Proportional to 287.73, 393.89 and 278.42

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Solution

The fourth proportional to 287.73, 393.89 and 278.42 is: 381.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.73 : 393.89 = 278.42 : x
  2. Step 2: Convert to fraction form
    287.73/393.89 = 278.42/x
  3. Step 3: Cross multiply
    287.73x = 393.89 × 278.42
  4. Step 4: Simplify right side
    287.73x = 109,663.49
  5. Step 5: Solve for x
    x = 109,663.49/287.73
  6. Step 6: Final answer
    x = 381.13

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.