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Finding the Fourth Proportional to 82.30, 123.47 and 28.20

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Solution

The fourth proportional to 82.30, 123.47 and 28.20 is: 42.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    82.30 : 123.47 = 28.20 : x
  2. Step 2: Convert to fraction form
    82.30/123.47 = 28.20/x
  3. Step 3: Cross multiply
    82.30x = 123.47 × 28.20
  4. Step 4: Simplify right side
    82.30x = 3,481.85
  5. Step 5: Solve for x
    x = 3,481.85/82.30
  6. Step 6: Final answer
    x = 42.31

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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.