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Finding the Fourth Proportional to 287.36, 398.14 and 281.21

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Solution

The fourth proportional to 287.36, 398.14 and 281.21 is: 389.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.36 : 398.14 = 281.21 : x
  2. Step 2: Convert to fraction form
    287.36/398.14 = 281.21/x
  3. Step 3: Cross multiply
    287.36x = 398.14 × 281.21
  4. Step 4: Simplify right side
    287.36x = 111,958.26
  5. Step 5: Solve for x
    x = 111,958.26/287.36
  6. Step 6: Final answer
    x = 389.62

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.