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Finding the Fourth Proportional to 287.72, 431.57 and 82.28

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Solution

The fourth proportional to 287.72, 431.57 and 82.28 is: 123.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.72 : 431.57 = 82.28 : x
  2. Step 2: Convert to fraction form
    287.72/431.57 = 82.28/x
  3. Step 3: Cross multiply
    287.72x = 431.57 × 82.28
  4. Step 4: Simplify right side
    287.72x = 35,511.06
  5. Step 5: Solve for x
    x = 35,511.06/287.72
  6. Step 6: Final answer
    x = 123.42

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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.